EmDm Gomez et dm:

State of the marine environment

in the East Asian Seas Region

UNEP Regional Seas Reports and Studies No. 126

Prepared in co-operation with

FA0 IOC

UNEP 1990 PREFACE

The better understanding of the changing problems facing the marine environment is a continuing goal of UNEP9s ocean programme, as it provides the necessary scientific background for shaping UNEP9s pol icy towards the protection of the oceans. The main sources of factual information used in the assessment of the state of the marine environment are data pub1 ished in open scientific 1 iterature, data available in various reports published as "grey literature" and data generated through numerous research and monitoring programmes sponsored by UNEP and other ~rganizations. Several procedures are used to evaluate critically the large amount of avai lable data and to prepare cons01 idated si te-specific or contaminant-specific rev i ews . GESAMP, the I~/FAO/Unesco/WMO/WHO/IAEA/UN/UNEP Joint Group of Experts on Scientific Aspects of Marine Pollution, is charged by its sponsoring bodies with preparation of global reviews. Reviews deal ing with several contaminants have been already published by GESAMP and others are being prepared for publication. The first global review on the state of the marine environment was also,~ublished by GESAMP in 1982, and the second global review was published in 1990 - . In parallel with the preparation of global assessments, the preparation of a series of regional assessments, following the general format of the second global review by GESAMP, was initiated by UNEP in 1986, with co-operation of the Food and Agriculture Organization of the United Nations (FAO) and the Intergovernmental Oceanographic Commission of Unesco (IOC) . Fi Steen task teams of scientists were set up, involving primarily experts from the relevant regions, to prepare the regional reports under the joint overall co-ordination of UNEP, FA0 and IOC, and with the collaboration of a number of other organizations. The present document is the product of the Task Team for the East Asian Seas Region. The final text of the report was prepared by E.D. Gomez, as Rapporteur of the Task Team for the East Asian Seas Region, with collaboration of E. Deocadiz, M. Hungspreugs, A. A. Jothy, Kuan Kwee Jee, A. Soegiarto, and R.S.S. Wu, whose contributions are gratefully acknowledged. The .report was edited and prepared for publication by Philip Torte11 of Environmental Management Limited, New Zeal and.

Pub1 ications of GESAMP are avai 1 able from the organizations sponsoring GESAMP.

i TABLE OF CONTENTS Page

INTRODUCTION

1.1 Aims of the report 1.2 Geographic coverage of the report 1.3 About the report

CHARACTERISTICS OF THE REGION

MARINE CONTAMINANTS

3.1 Concentrations (levels and distribution) in water, sediments and biota 3.2 Transport and f 1uxes across boundaries 3.3 Quality assurance, data validation and management

HUMAN ACTIVITIES AFFECTING THE SEA

Disposal of urban and industrial waste waters Development of coastal areas Manipulation of hydrological cycles Other land use practices Disposal of contaminated sediments, mine tai1 ings and solid industrial wastes Disposal of sol id matter (1 itter) Marine transport of oil and other hazardous substances Exploitation of non-living marine resources Exploitation of living marine resources

BIOLOGICAL EFFECTS

5.1 Eutrophication and associated phenomena 5.2 Public health effects 5.3 Damaged habitats and resources and their potential for recovery and rehabilitation 5.4 Accidents and episodic events

PREVENTION AND CONTROL STRATEGIES

TRENDS AND FORECASTS

ECONOMICS

SUMMARY

10. REFERENCES

APPENDIX: NAMES AND ADDRESSES OF CONTRIBUTORS 1. INTRODUCTION

1.1 Aims of the report This is a first attempt to provide a perspective of the state of the marine environment in the East Asian Seas region. It is the initial review in a series that will be conducted periodically. Through such an exercise, it is hoped to document the trends in marine contamination in the region as well as general marine ecosystem health. It will be recognized that factors other than pollution may have significant impacts on the we1 1 -beinG or condition of natural habitats. Whi le amel ioration of deteriorating trends is welcome and sometimes seen, more often than not it is cost prohibitive. This report and subsequent ones should therefore be helpful to decision-makers at a1 1 levels, national, regional, and international, to provide the database for the management of the marine environment. It is envisaged that the report will also guide potential sponsors from the private sector and the international community to subsidize activities in the region that are apt to contribute to the understanding and betterment of the marine environment. This report is intended to serve as a reference document to the global review of the state of the marine environment referred to below. 1.2 Geo~raphiccoveraqe of the report

The region covered by this report is Southeast Asia (Fig. 1). It is bounded on the north by the South China Sea and the Phi 1 ippine Sea; on the west by the Andaman Sea? the Straits of Malacca and the Eastern Indian Ocean; through to the Timor Sea and the Arafura Sea on the south; and the Pacific Ocean on the east. Other significant marine areas include the Gulf of Thailand, the Java Sea, the Sulu Sea, the Sulawesi Sea, the Straits of Macassar? the Flores Sea, and the Banda Sea. The Asian mainland is on the northwest sector while the Australian subcontinent is on the southeast sector. In between these two land masses are the two large archipelagoes of Indonesia and the Philippines with more than 20,000 islands of a wide range of sizes.

1.3 About the report It is acknowledged that the data used in this report are not comprehensive. Whi le this is partly due to the 1 imitations of the task team members in not being able to access all available data? it is more a reflection of the state of knowledge of the status of the marine environment in the region. As explained in subsequent sections, much data have been discarded due to lack of quality assurance. Even more basic is the fact that the number of studies of any specific contaminant or ecosystem have been few and far between. Hence* the overall picture is far from complete but the image is forming. It is hoped that with each succeeding review, the mosaic wi 11 become more complete. As this report was being completed, two publications of relevance were about to be published but were not available to the task team. The reader is referred to the special issue of Ambio, Journal of the Human Environment, on the East Asian Seas region for recent papers on the marine environment of the area (Vol . 17 No. 3, 1988). And, for a more comprehensive reference on oi 1 pollution in the region, the Proceedings of a Meeting of Experts on the Control of Oil Pollution in the East Asian Seas Region have just been issued as No. 96 of the UNEP Regional Seas Reports and Studies series (Yap et a1 , 1988).

2. CHARACTERISTICS OF THE REGION

Southeast Asian waters comprise the Andaman Sea, the Straits of Malacca, the Straits of Singapore, the South China Sea, the Java Sea, the Flores Sea, the Banda Sea, the Arafura Sea, the Timor Sea, the Celebes Sea, the Sulu Sea, and the Phi 1ippine Sea. The whole body of water covers 8.94 mi 11ion square kilometers in area, which represents about 2.5 per cent of the world's ocean surface. The southeast Asian marine realm includes shallow continental shelves, deep sea basins, troughs, trenches, continental slopes and volcanic and coral islands. The numerous large and small islands divide the waters into different seas connected by many channels, passages and straits.

Located between the Asian and the Australian continents, the southeast Asian region is strongly influenced by monsoons. The north monsoon in southeast Asia lasts from December to February and the south monsoon from June to August. The rest of the year represents the transition from the north to the south monsoons (March to May) and from the south to the north monsoons (September to November).

The oceanographic characteristics be1ow are drawn from Soegi art0 (1985). The water mass of the Southeast Asian region originates from the Pacific Ocean. This is clearly indicated by surface current patterns in the region. The North Equatorial Current flows westwards and upon reaching the Phi 1ippine is1ands, spl its into 2 main branches. The northward branch becomes the Kuroshio, and the southward branch, the Mindanao Current. The Kuroshio begins east of northern Luzon as a swift and narrow segment of the western boundary current and flows to the east coast of Taiwan, the East China Sea and the Japan Sea. During the north monsoon, the Kuroshio is deflected into the China Sea. The Mindanao Current flows southeast with a speed of 1 or 2 knots along the coast of Mindanao Island with its main part entering the Celebes Sea through the straits between Mindanao, Sangir and Talaut Islands.

The tides of southeast. Asian waters are affected by both the Pacific and the Indian Oceans. Diurnal tides predominate in the South China and Java Seas, whereas mixed tides prevail in the eastern Indonesian archipelago, Philippine waters, the Andaman Sea, Straits of Malacca, and the shelf areas northeast of Australia.

Since the Southeast Asian region straddles the equator, the surface water is characterized by high temperature. This property combined with the influence of low salinity reduces the density of the surface water rather markedly. The large excess of rainfall over evaporation causes an average salinity of less than 34 parts per thousand within a region enclosed by a 1ine running from Sri Lanka, off the islands of Sumatra, Java, Celebes and Philippines to Taiwan.

One of the features of tropical waters is that the surface layer is warm and the annual temperature variation is small. During the north monsoon, generally high surface temperatures of 28-30° prevail on the west coast of Sumatra and the eastern Indonesian archipelago waters. However, because of the inflow of water masses from higher latitudes, colder water (26-27OC) is found in the South China Sea. Temperatures of 26-27OC also prevail in the Arafura Sea and the south coast of Java. In other waters, temperatures range between 27OC and 29OC.

The average annual range of sea surface temperature in the equatorial region is less than Z° but is slightly higher, 3OC to 4OC, in the Banda Sea, the Arafura Sea and Timor Sea as well as in the waters south of Java. The salinity in southeast Asian waters is extremely variable. The effects of high rainfall, run-off of many large rivers, and geographical subdivisions of the seas are responsible for this characteristic. The distribution of discharges from land, presence of large bays and channels with 1 ittle water exchange contribute to the general lowering of the salinity. The monsoons cause rainy and dry seasons which then also affect the annual variation of salinity. In general, the surface dissolved oxygen (DO) does not show a strong seasonal variation. DO concentrations for the eastern Indonesian archi pel ago are 4.0 to 4.5 mill at the surface and 2.5 and 3.0 mill at depth; for the Sunda Shelf, 3.5 and 4.0 mill; for the area of Mindanao current, 4.5 mill; for the south coast of Java, 2.5 to 3.0 ml/l at the coastal area and over 4.0 mill towards the open sea; and for the South China Sea, 2.5 and 3.0 mill. Several factors influence the water tranparency, e.g., silt content, plankton and other particulate matter in the water. Low water transparency (less than 10 meters deep) is found in the areas of river mouths and in coastal waters around Sumatra, Borneo, and the Gulf of Thailand. In general, the transparency is higher in the deep water (between 10 and 20 meters) and in the open seas (20 to 30 meters). Turning to the land, the population of the six ASEAN countries and Hong Kong is in the order of a little under one third of a billion people. The region is considered developing and predominantly agricultural, with industries concentrated around a limited number of cities which characteristically have high population densities (2 to 8 million). Under the ci rcumstances, the mari ne envi ronment has been inf 1 uenced more and more by human activities with the degree of contamination being most pronounced near coastal population centres. The concern of individual governments to safeguard the marine environment from further degradation was trans1 ated into a regional effort with the development of an action plan initially for the member states of the Association of Southeast Asian Nations (ASEAN) . The East Asian Seas Action Plan was adopted in 1981 and since that time, more than half a dozen regional projects have been implemented by national institutions in five countries. The succeeding chapters present a summary of the available data on marine contamination in the region, specifically from Hong Kong, Indonesia, Malaysia, the Phi 1 ippi nes, Singapore and Thai land.

3. MARINE CONTAMINANTS Concentrations (levels and distribution) in water, sediments and biota Data on the concentration of contaminants in sea water and sediment have been very sparsely reported in the EAS region, a region which is still in its infancy in the context of marine pollution monitoring. Laboratories are often faced with the problems of inadequacies in faci 1 ities, qua1 ified personnel and funds to carry out this task. Besides, the measurement of heavy metals and chlorinated hydrocarbons in sea water, in particular, requi res greater accuracy and sophistication in methodology, owing to their levels being generally a few magnitudes below those in biota. Concentration in water Trace metals This is perhaps the most difficult analysis among the three media considered as the levels of trace metals in sea water are very low compared with the concentration of major elements. Contamination can be easily introduced in all stages - sampl ing , storage, analysis and concentrat ion measurements. Hong Kong, Malaysia and the Philippines did not report data of heavy metals in sea water. Singapore reported a trend, decreases in Cd and Pb, but a slight increase in Cu from 1980 to 1985, using atomic absorption spectrophotometry. In 1985, mean Cu concentration varied from 2.0 to 2.9 pgll. Thailand reported the following figures for 15 stations in the Upper Gulf of Thai land (Hungspreugs, 1985), in pgll . November 1984 (f 1 ood season) March 1985 (dry season) Cd mean range Cu mean range Pb mean range Zn mean range N.B. Detection limits are: Cd - 0.005, Cu - 0.01, Pb - 0.005, Zn - 0.5, using the co-precipitation method with CoCl - APDC (Huizenga, 1981), then flameless AAS for Cd, Cu and Pb, and flame AAS for In. A1 1 preparations were performed under laminar flow cabinet or 'clean bench Class 100'. The concentration of heavy metals in some local ized coastal waters of Indonesia has been reported to be very high. Among these are the coastal waters of Jakarta Bay, Surabaya and the Straits of Malacca. Studies by Razak et a1. (1984) indicated the severity of heavy metal pollution in Jakarta Bay - Cu, Hg, Pb and Cd levels (0.16, 0.013, 0.31 and 0.19 mg/l, respectively) were found to be higher than the standard set by the Indonesian government: Cu, 0.06 mgll ; Hg, 0.006 mgll ; Pb, 0.075 mgll; and Cd, 0.01 mg/le Petroleum hydrocarbons Hong Kong reported the levels of dissolved petroleum hydrocarbons in open sea water to be 12-20 pg/l, but near fishing villages, typhoon shelters and marinas, a single measurement showed up to 125 pg11 (Chan & Jie, 1977). Singapore measured oil and grease in sea water and found the ranges 1-18 (average 4.2) and 0.1-9.2 (average 1 .O) pg/1 in 1980 and 1985 on the west coast and an average of 2 pgI1 in the Straits of Johore (west) in 1980 and 1985. The Philippines also reported oi 1 and grease in marine water, for example, for Manila South Harbour, at 1.76-5.11 pg/1 (National Operation Center for Oil Pollution, 1978 unpublished data) and Cebu 0.66-5.05 pgll. For Thai land, Sompongchaiyakul et a1. (1986) reported the fol lowing levels (as chrysene equivalent, IOC - UVF method) for the Gulf of Thailand. April (dry season) September (wet season)

Near river mouths 2.94 + 1.84 Mi d-Gul f 0.30 + 0.25 East Coast, Upper Gulf 0.38 + 0.34

Di ssol ved and di spersed petrol eum hydrocarbon (DDPH) measurements in water samples from the Upper Gulf resulted in a mean concentration of 2.3 pg/1 crude oil equivalents, with the range from 0.65-8.3 ng/l. In the Lower Gulf the range of hydrocarbons found was 0.07-6.6 pg/1 and the mean was 1.3 pg/l. There is no significant difference in the amounts of DDPH observed between the samples collected during the dry (Apri 1) and wet (August) seasons nor between the Upper and the Lower Gulf. However, a significant correlation was found between DDPH concentrations and tidal stage, especially for river mouth stations (Wattayakorn, 1987a) . Indonesia being an oil producing nation and a major route for transporting petroleum and petroleum products, hydrocarbon pollution in its waters, especially in Jakarta Bay, was critical. Wisaksono (1974) recorded that samples taken around the harbour have concentrations of 60 to 100 pgll, whereas samples collected away from the harbour registered a concentration range of 0.5 to 4.00 pg/1 (Martin et a1, 1983). Widespread occurrence of tarballs was a1 so noted on the beaches of Pari Island Group, Jakarta Bay. Toro & Djamal i (1982) reported seasonal variation ranging from 0.28 to 2101.37 g/sq. m.

For Malaysia, Law & Yusof (1986) reported in the Matahari Expedition Report that the South China Sea off Terengganu coast showed very high overall mean dissolved hydrocarbon levels in the range 960-990 pg/1 at 1 m, 10 m and 20 m depth for two-thirds of the stations and the rest was between 160-170 pg/1. The high values were probably the result of offshore oil and gas exploration and exploitation activities in the area. One year after, Law & Mahmood (1987) investigated the area further south, off the coast of Kuantan and Pulau Tioman and found lower levels at around 38 pg/1 from 1-50 m depth. Chlorinated hydrocarbons For the Philippines, from 1976 to 1982, marine waters in 9 areas were analyzed for alpha-, beta- and gamma-HCH, aldrin, dieldrin, endrin, heptachlor, heptachlor epoxide and p-p-DDT.

a1 dri n trace - 0.180 a1 pha-HCH trace - 0.063 beta-HCH 0.008 - 0.063 gamma-HCH trace - 0.299 dieldrin trace - 0.088 endri n trace - 0.024 heptachl or trace - 0.059 heptachlor epoxide trace - 0.022 p-p-DDT 0.012 - 0.112

(Ref. Phi 1i ppi nes , 1980) . For Thailand, Thoophom et a1. (1984) analyzed water samples from mussel and oyster growing areas of the tipper Gulf of Thai 1and for DOT, PCB, heptachlor, aldrin, chlordane, endosulfan and found only DDT in 9% of the samples from 8 sampling surveys throughout the year 1983. The maximum concentration was 0.011 ug11 Concentrations in sediments

Trace metals

The levels of Cu and Zn in Victoria Harbour, Hong Kong, sediments at 111 and 247 pglg dry weight respectively, were some 5 and 2.5 times higher than those in other Hong Kong areas (mean: 22 and 96 \iq/g respectively), although the Fe level (as reference metal) at 31,560 pg/g was about the same as the mean of 33,120 pglg for other areas. This can be related to urban and industrial discharges in Victoria Harbour. Contamination of sediments by Cu, Zn and Pb, was less marked in Deep Bay (Yim & Fung, 1981; Phi 11ips & Yim, 1981) .

(Methodology of metal analysis : a sample of the 470 pm fraction was digested in a 4:l v/v nitric : perchloric acid mixture, and metal concentration determined by f 1ame atomic absorption spectrophotometry) . For peninsular Malaysia, metal concentrations in sediments from 14 stations in the South China Sea ranged from 0.41-2.39 pg/1 for cadmium, 1.94-9.21 pg/1 for copper, 12.45-49.88 pg/g for zinc, 6.09-22.30 pg/g for nickel and 1.94-12.76 pg/g for lead. These metal levels indicate that the study area is unpol 1 uted (Noor Ahzar et a1, 1987).

For the Upper Gulf of Thailand, monitoring of 18 stations in 1982 showed the following results for "strong HNO, leaching" of Al, Fe, Mn, Cu, and Ni in sediments.

From this work, it was found that cone. HNO leached out 39-68% of A1, 68-92% of Fe, 72-100% of Mn, 36-85% of Cu and 100% of %ias compared to the total digest ion method (Windom et a1 , 1984) . The following are trace metal concentrations in HNO, -acid digested sediment samples from the south western portion of the South China Sea (Noor Azhar et a1, 1987):

The low metal concentrations are indicative of a non-polluted marine environment. This is to be expected because the sampling sites are located offshore. Another indication of heavy metal pollution in Jakarta Bay, Indonesia is the high levels of Hg, Cu, Mn, Zn, Fe, Cd, Ni, Co and Cr in sediments (Martin et a1, 1983).

Cone. Range (mglkg) except for Fe in %

Petroleum hydrocarbons From the two 1982 surveys in the Upper Gulf and the Eastern Seaboard of Thai 1and, the fol lowing results were obtained (chrysene standard, IOC Manuals and Guides) in pglg dry weight.

Apr i 1 September Near river mouths 0.711 + 0.876 0.186 + 0.084 Upper Gulf (West) 0.138 + 0.038 0.088 + 0.043 Mid Gulf 0.069 + 0.088 0.092 + 0.032

There did not appear to be significant differences in the concentrations for the dry and wet seasons except for the river mouth stations, probably due to the dilution effect of- fresh water at the flood season (September) (Sompongchaiyakul et a1, 1986). Using crude oil as standard, Wattayakorn (1987b) reported the range of hydrocarbons at 0.70-62 pglg in the Upper Gulf and 0.03-8.3 pglg in the Lower Gulf. The highest concentrations of hydrocarbons were found in areas of high anthropogenic activities. The results show the sediments of the Lower Gulf to be relatively uncontaminated by- hydrocarbons- of petroleum or other fossi 1 fuel origin, and that the upper Gulf area is generally only lightly contaminated (~attayakorn, 1987b). This study has shown that concentrations of hydrocarbons were higher in samples from river mouth and coastal stations due to land-based and boating activities, run-off from land and introduction via seawage outfalls. Concentrations of hydrocarbons are generally three to four orders of magnitude higher in sediments than in the water column for the same study area which were previously reported by Wattayakorn (1987) . Indonesia reported hydrocarbon concentration in sediments from Jakarta Bay to range from 9.0 to 331 pglg. The highest concentration was found from samples just outside the Sunda Kelapa and in the Tanjung Priok harbours. Law & Mahmood (1987) reported the oil concentration in the offshore Terengganu at 6.43-1332 pglg while the surface sediment off Kuantan coast showed an average of 42.92 pglg. Obvious1 y the higher value areas were very polluted. Chlorinated hydrocarbons No data are available for most countries. For Thailand the average value of DDT for 5 stations on the Andaman Sea coast was 0.002 ~glgdry weight whi le the average for the Upper Gulf of Thailand was 0.008 pg/g (Hungspreugs & Wattayakorn, 1978) . In Indonesia, Martin et a1. (1983) reported DDT concentration to range from 1.0 to 13.0 pg/g and PCB levels from 4 to 9 pglg in Jakarta Bay. Concentrations in biota Heavy metals The contamination of marine biota by heavy metals and chlorinated hydrocarbons (Tables 1 and 2), is a1 so inadequately reported in the EAS region. By nature, the levels of heavy metals in oysters (Crassostrea) are of a different order of magnitude than those of mussels and clams (Forstner & Wittmann, 1981). Levels for heavy metals in biota in Thai land are provided by Huschenbeth & Harms (1975) for fish and by Hungspreugs & Yuangthong (1984) for oysters and mussels. Petroleum hydrocarbons Very little information is available on petroleum hydrocarbon contamination in marine biota in the EAS region, except for a single set of records from biota in the Gulf of Thailand taken in 1986 (fish: 0.12-0.60 mglkg; shellfish: 0.06-2.38 mglkg) , which suggest conditions simi lar to a relatively unpolluted area (Sompongchaiyakul et a1, 1986). Chlorinated hydrocarbons From the meagre information avai 1 able on chlorinated hydrocarbons in marine biota (Table 3.2), it is not possible to assess the extent of contamination in fish and bivalves in the EAS re ion. In Hong Kong, only 73 km of land is arable so the use of pesticides is low ?only about 150 tonnes active ingredients per year) and there is no local production. There is no data on chlorinated hydrocarbons in water, only in mussels and human milk samples (Ip, 1983) which showed twice the DOT and HCH level as in the average human milk. Minor quantities of HCB and PCB were found. In another study, out of the 15 stations sampled, only mussels, Perna viridis, from 2 stations show very high levels of DDT and PCB, up to 2.043 mglkg and 1 .go4 mglkg respectively(Phi 11 ips, 1985). In Thailand, the trend is very clear that during 1973 to 1983, the uses of more toxic organochlorine group of pesticides was fast decreasing resulting in much lower levels of such compounds in the marine organisms (Vongbuddhapi tak et a1, 1985). The investigations on 80 species of fish, shrimp, squid and bivalves show a range of ~0.01-0.03 mglkg wet weight. Radioactive contamination Information on radioactive contamination in marine biota is lacking in the EAS region, except for a single record from Thailand taken in 1984 (fish: 1.5-2.1 pclg; shellfish: 0.2-1.6 pclg), which may be considered to be comparable to that of ambient levels (Polphong et a1, 1984). Table 1. Concentration (mglkg) of heavy metals in marine biota

Locality Cd Cu Hg Pb Zn Remarks

Straits of Ma1 acca:I7 Fish (1983) Trace 1.7 Ambient 1.20 10.8 Shel l f ish (1983) 0.25 9.2 Ambient 0.74 25.2

Singapore waters :I7 Fish No data Shel 1fish (1974) 2.10 - 1.30 - Ambient 2.70 - 1.60 - Indones ian Waters :I7 Fish (1979) 0.09 0.30 Pol luted 0.68 9.96 Shel 1fish (1979) 0.68 11.31 Polluted 19.85

South China Sea: No data

Gulf of Thai land: Fish (1975)~' 0.01 0.01 6.2 Ambient 0.06 0.09 11.8 -Perna viridis 0.13 0.54 78 Ambient (1984)~' 1.05 2.05 20 1 Crassostrea commercial is 0.76 1.51 424 Ambient (1984)~' 5.02 5.19 1347 Phil ippine waters:IJ Fish (1974-1985) Trace Trace 0.01 0 .O1 0.2 Polluted 0.36 4.43 1.10 0.08 58.4 Shel 1fish (1975-1982) 0.02 2.36 0.02 0.04 10.4 Pol luted 3.84 51.90 0.84 2.20 201 .o Hong Kong Waters :v/2115' Fish (1976-1979) Trace Trace Trace Trace 2.3 Ambient - 0.3 0.1 - 6.6 Trace Trace Trace Trace 0.8 Polluted - 1.1 0.4 0.3 25.4 Shel lfish 41 Trace 1.1 Trace Trace 10.1 Ambient (1976-1979) - 35.2 0.1 3 .O 105.0 Trace 6.3 Trace Trace 13.5 Pol 1uted 5.4 309.0 1.3 0.4 662.0

-I/ values expressed in terms of wet weight. -21 minimum and maximum values. -31 values expressed in terms of dry weight. -41 including molluscs and crustaceans -51 The above levels are compi led based on a1 1 the existing published data on metal levels in fin fish, oysters, crustaceans and other molluscs. Table 2. Concentration (mg/kg) of chlorinated hydrocarbons in marine biota

Locality DDT -HCH -HCH Dieldrin Aldrin Heptachlor Heptach Lor PCB' s Remarks

Straits of Ma1acca:- / Fish (1983) 3.s7 - 1.O Trace - - - 20.0 Ambient 16.0 12.0 4.0 40.0

Shellfish (1983) - 27.0 Ambi ent 44.0

Singapore Waters -- No data

Indonesian Wafers No data .-

South China Sea No data

Upper Gdlf of Thai land:-1 / Fish (1985)

Bivalves (1985)

Philippine Waters:-I Fish (1976-1985) Trace Trace Trace Trace Trace Trace - Ambient 0.80 0.50 0.10 0.10 0.20 - -

Shellfish (1982) 0.30 Trace 0.01 - Ambient 0.09 0.03 0.03

Hong Kong Waters:-3 / Fish No data Shellfish (1985) Trace Trace - - - - Trace Polluted 2.04 - 0.21 - - - 1.90

I/ values expressed in terms of wet weight 2/ maximum and minimum values j/ values expressed in terms of dry weight -4/ values for BHC >/ nd - non detectable 3.2 Transport and fluxes across boundaries The transport of sediment by rivers into the sea has been recognized as a growing problem in Indonesia. Watersheds or catchment basins dominated by sedimentary formations are more susceptible to erosion than those of volcanic geology (Mei jerink, 1977). The increasing rate of erosion is exemplified by a study of Soemarwoto (1974) who showed that the sediment load of the Citarum River rose six-fold in a two-year period. For Malaysia, the amount of surface soi 1 transport from peninsular Malaysia into the Straits of Malacca was 26 million tonneslyear. From peninsular Malaysia to the South China Sea, it was 22 mi 11 ion tonneslyear (Jaafar, 1986). Soi 1 erosion in the Philippines has been estimated at 500 mi 11 ion tonnes per year because of the extensive loss in vegetation cover (de Vera, 1978). For Thailand, it has been estimated that during 1981-1983 the suspended sol id load into the Gulf of Thai land was 3.95 mil 1 ion tonneslyear, BOD 75.7 million kg/year, nitro en 57.9 mi 1 1 ion kglyear, and phosphorus 9.4 mi 1 1 ion kglyear (Thailand, 19841 . 3.3 Quality assurance, data validation and manaqement Although it is accepted in principle that data quality is of utmost importance, in practice intercomparison exercises of contaminant analysis are still very limited in this region. Only a small number of laboratories participate in such activities. The activities are limited to chemical analysis of prepared samples, but none on sampling methods and storage, especially of water for trace metal analysis, in which a lot of errors are sti 11 made. The acid reagents used in sample preservation and in the analytical methods themselves are very often the major source of errors in trace metal analysis. As a result of more concern and care on this problem, the reported levels of trace metals in natural waters of Thailand seem to be decreasing greatly and probably data generated before 1981 are no longer acceptable. Recently, a very useful US NOAA pub1 ication became available - "Reference Materials for Marine Science" which helps marine chemists to locate the desired reference and standard materials in this field. In Hong Kong, a1 1 samples for conservative pollutant analysis are collected by various government agencies but the analysis is performed at the central laboratory which maintains very high standards and observes strict quality control. The Malaysian laboratory (Fisheries Research ~nstitute) responsible for carrying out the measurements of organochlorine and heavy metals in marine biota has been following the ICES method and has participated in the IOC/GEMSI intercal ibration exercise but the results were not yet avai lable to participants at the time of writing. In the Philippines, two laboratories participated in an intercalibration exercise on metals and their results are acceptable for Cu, Cd and Hg. The results for other metals must be interpreted with caution. They also took part in an organochlorine intercal i bration exercise of IOCIUNEP but the results are not yet avai 1 able. In Singapore, analysis of samples is done by well-trained technicians in well-equipped laboratories with the use of procedures in the "Standard Methods for Water and Wastewater Analysis". In Thai 1 and, some laboratories have taken part in the FAOIIOC-organized intercalibration exercises but the results varied from metal to metal. One laboratory obtained acceptable results with their samples from the IAEA, using the neutron activation method. Another 1 aboratory analyzed reference samples side by side with the unknown samples to check the results. For water sample analyses, calibration was made with reference to sea water, river water and estuarine water from the National Research Council of Canada.

4. HUMAN ACTIVITIES AFFECTING THE SEA 4.1 Disposal of urban and industrial waste water Sewage (human and domestic waste) is the major source of organic pollution in various populous coastal areas in the region. As a result of population growth, there is a steady increase in sewage discharge. While varying degrees of treatment are employed in some localities, disposal of untreated sewage directly or indirectly (e.g. via rivers and waterways) is the general practice. For instance, in Thailand, pollutants discharged from the Chao Phraya River are the major contribution to coastal water pollution. An estimated net BOD reaching the Gulf of Thailand via this river alone is 114,670 kglday. The estimate for all the rivers emptying into the Gulf is 305,212 kglday (Thai land, 1984). Law (1986) investigated the extent of domestic sewage pollution in Kelang coastal waters in Malaysia. Faecal col iform count was used as an index. Very high counts of faecal coliform bacteria were found at the river mouth where the mean value was 3.0 x lo4 MPNI100 ml . The heavy load of faecal col iform bacteria in the sediment from the river mouth, 360 MPN/g dry sediment, also reflected strong sewage pollution in this area. Low counts were detected in the water about 10 km from the river mouth, mean values being 31 - 54 MPNI100 ml while for the sediment, the values were 3.8 - 3.9 MPN/g dry sediment. These levels were below the safety limit recommended for recreational waters (100 MPNI100 ml) . The result of this study suggested that the extent of sewage pollution in Kelang coastal waters was confined within 10 km from the Kelang River mouth. The success of Singapore in reducing water pollution significantly overthe past years is a noteworthy exception in the region. Today, modern sanitation facilities are available to 97% of the population, compared with 55% in 1972 (Singapore, 1986). In addition, the Sewerage Department operates an industrial water works to recycle waste water for industrial use in the Jurong industrial area. In 1985, an average of 12,924 m3 of industrial water was sold each day. Also commendable is the massive clean-up of the Singapore River which involved resiting street hawkers in markets and food centres with proper sewerage and refuse removal facilities, dredging of dumped garbage (amounting to about 30 tonnes) and removal of flotsam. After 8 years, about 90% of pollution was eliminated. The river has been transformed into a major touristlrecreation area from a "murky, smelly backwater crowded with 1 ighters and 1 ittered with rubbish" (Anonymous, 1984). A hydrological survey of the previously 1 ifeless waters revealed 39 species of organisms consisting mainly of bivalves, crustaceans, polychaetes and fish. The decrease in the faecal coliform levels in the coastal waters of Singapore attests to the remarkable reduction of water pollution in this country. Average faecal counts decreased from 43 MPNI100 ml and 126 MPN1100 ml in 1980 to 18 MPN1100 ml and 32 MPNI100 ml in 1985 for the western and eastern coasts, respectively. Even more dramatic is the decrease in the Strait of Johore where average faecal coliform counts went down to 64 and 137 MPNI100 ml in 1985 from 320 and 521 MPNl100 ml in 1980 for the western and eastern sections of the strait, respectively (Kuan, 1987). The overall improvement on the state of the Strait of Johore waters in recent years, with respect to organic pollution was attributed to a great extent to the improved quality of discharges from Singapore. For most developing countries in the region, however, it appears unlikely that the quality of sewage effluents will be improved significantly in the near future considering the escalating quantities and phenomenal costs in central treatment facilities at the secondary and tertiary levels. In addition, livestock wastes (i.e. piggeries, poultries) are also discharged in the raw form. However, in Malaysia, more stringent environmental regulations requiring livestock wastes to be subjected to primary treatment in oxidation ponds prior to disposal, are expected to improve the quality of these effluents in the future. Organic inputs from various industries (e.g. pulp and paper mills, sugar mills, soft drink plants, etc.) in more industrial ized areas are also considerable. More industries, however, are treating their wastes with the advent of stricter enforcement of environmental regulations and remarkable advances in treatment technology. Notable in this respect is the significant reduction of the net organic load of palm oil and rubber effluents in Malaysia by 97% and 80%, respectively, over a period of five years (1980-1985). Anoxic conditions in bottom waters due to high organic load have been reported in various localities (e.g. portions of the Straits of Malacca, Manila Bay, Victoria and Tolo Harbours in Hong Kong). In enclosed/semi-enclosed areas in Victoria Harbour, anoxia occurs transiently or permanently. In this particular area, the average oxygen saturation steadi ly declined from 83.4% in 1973 to 61.5% in 1983 (Fig. 2). Recent hydraulic and pollution model 1 ing studies in this harbour have shown that any additional pollution loading could cause unacceptable levels of oxygen (~50% saturation). A similar decline in the oxygen levels in Tolo Harbour, has been noted (Fig. 2) . Decrease in oxygen levels was reported to be further aggravated by the development of the summer thermocl inelhal ocl ine. Unfortunately, no drastic improvement in water quality has been found since the commissioning of two sewage treatment plants in 1982.

Morgan & Valencia (1983) have shown the distribution of population concentration, sewage pol 1 uti on and organic pol 1 ut i on in terms of biochemical oxygen demand (BOD) in selected localities in Southeast Asia (Fig. 3). Of these localities, the highest BOD from industrial sources was reported from Manila while that from domestic waste was reported from the coastal waters of the Upper Gulf of Thai 1 and. In Thailand, fishery factories located at the Ta Chin River mouth, discharged wastewaters containing high phosphate (over 70 mgll), nitrate (180-275 mg11) , ammonia (30-35 mgll) and organic matter (6,500-28,000 mgll) , but the volume released into the water was small in comparison with the municipal waste or industrial waste from distilleries. Of the nutrients in the Chao Phraya River mouth, the organic fraction of nitrogen was about 95% while that of reactive phosphorus was 50% (Si lpipat & Champongsang, 1981) . At present industrial wastes in Indonesia are still rather limited and localized as compared to other sources of pollutants. However, it can be expected to be very important sources in the future, particularly with the current government drive for industrialization in many sectors of the economy.

On the whole, there is little or no evidence of toxic contaminants being released in high concentrations through industri a1 waste waters in the region. The discharge of cooling waters in coastal seas from industries like power generating plants cannot be totally disregarded. Besides the oily residues of the effluent, more important is the heat that is dissipated into the coastal waters. Unfortunately, there is also 1ittle information on this although it is most 1i kely that impacts from cool ing waters are very local ized and not as widespread as in temperate areas. As an example, only a few steam-power electric generators are operating now in Indonesia with a total capacity of only about 750MW. Therefore, the volume of thermal waste fromthese plants is still relatively small. However, this condition wi 11 change rather drastical ly when the Indonesian Government starts to implement a plan to multiply electric power generation in Indonesia. 4.2 Development of coastal areas Rapid population growth and the drive for economic development have brought about continued development of coastal areas in the region. One of the major modifications in the coastal areas is land reclamation. As far back as the early 1970s, the natural coastal area fringing Hong Kong Island and Kowloon had almost been totally reclaimed (Fig. 4). Some 3,600 ha of land have been reclaimed around Victoria Harbour. The area reclaimed in recent years (1982-1985) is shown in Table 3. In most other countries in the region, reclamation of mangrove areas for industri a1 sites, housing projects, drainage systems, agricultural and aquaculture developments is prevalent. In Singapore, 10-12% of the total land used to be mangrove areas; today, only 3% remains and reclamation is sti 11 going on. In addition, some coral reefs have been adversely affected by the reclamation activities.

Table 3. Total coastal area reclaimed in Hong Kong (in ha.) from 1981 to 1985 (Wu, 1987).

YEAR Total area reclaimed (ha.)

Of the 2.5 mi 11 ion ha of mangrove area in Indonesia, 200,000 ha were converted for agriculture between 1969-1974 and an additional 500,000 ha for rice fields and fish ponds, among other uses, during the period 1974-1979 (Soegiarto & Polunin, 1981). Between 1979-1999 another half mi 11 ion hectares of coastal 1and are projected to be converted to agricultural land. There is a national plan to develop additional 100,000 ha of shrimp ponds. The main objective of this plan is to promote the culture of penaeid shrimps for export. Since mangrove areas are most suitable to be developed for shrimp ponds, large areas of mangrove have been converted into shrimp ponds without any consideration for the potential long term envi ronmental consequences. Likewise, in Malaysia, about 20,000 ha of the 570,000 ha of mangrove coastlines have been reclaimed. As much as 114,000 ha more are expected to be converted for similar developments in the years to come (Jothy, 1984a). Available data from the Philippines indicate that by 1952, 88,681 ha had been converted to fishponds. By 1982, the area had increased to 195,831 ha. Many limited areas have been converted from mangrove swamps to agricultural land and other uses. Thus, of an original mangrove area exceeding 400,000 ha, only about half remains. Moreover, of the remaining area, another half has been exploited to a greater or lesser degree so that only 106,133 ha are presently covered by mangrove vegetation. Inevitably accompanying coastal development is the problem of domestic and industrial discharges discussed in the first section. Subsequent impacts on the marine environment occur in varying degrees. Reclamation considerably decreased water circulation in some portions of Manila Bay and is thought to contribute to increased coliform counts in these areas. Similarly, the reduction of Victoria Harbour due to reclamation up to 1985 has reduced tidal flushing and augmented pollution due to sewage discharges. Reclamation of the airport runway has also seriously reduced water flow near Kowloon Bay making the waters permanently anoxic and devoid of benthic communities. Comparative studies on the structure of littoral communities on 12 reclaimed shores of different ages in Hong Kong suggest that it would take 8-10 years to reach a climax community. Moreover, since reclamation may have changed the shore type, substratum and surrounding hydrography, recol oni zaton by a different type of community may occur. Posing more serious impact on the marine environment in many countries in the region is the increase in sediment load resulting from various activites such as reclamation, dredging and harbour construction in addition to improper land use (e.g. denudation of forests and mangroves, bad agricultural practices). Ma1 aysi an fishermen in the Straits of Malacca claim that offshore dumping of inert dredge spoi 1s has driven fish from their fishing grounds. These activities also contribute significantly to degradation of coral reefs in localized areas throughout the regi on (Yap & Gomez , 1985) . Harbour construction is taking place with greater emphasis along the less developed Malaysian coasts bordering the South China Sea. This is expected to bring about a significant increase in sediment load in the neighboring waters. A related development is that of tourist resorts along both east and west coasts of peninsular Malaysia, which will result in increased sewage discharge. Of greater concern is the establishment of industrial estates in various parts of the country. Effluent from these will have a greater impact on coastal waters. Enhanced sedimentation through serious soil erosion due to poorly planned agriculture and forest exploitation was thought to be the worst human impact on Indonesian estuaries. Apart from these, some reefs along the north coast of Java have been buried due to similar activities and reclamation (Soegiarto & Polunin, 1981). It was also reported that inorganic pollution in Malaysia particularly due to soil erosion and river siltation is more serious than organic pollution (Jaafar,

1986). On the other hand, it is notable that in 1985, the Strait of Johore was found to be free from the presence of high levels of suspended sediments. This was a marked improvement over the earlier years when the strait was very turbid (Ma1 aysia, 1986a).

As an archipelago, Indonesia has to develop rather intensive sea transport and harbour infrastructure, be it for national or for international trade. Coinciding with this scheme, and for easier accessibility, more and more industrial estates have been developed in the coastal area. A few examples can be mentioned here: Pulau Gadung in Jakarta, Gresik and other parts of Surabaya (east Java), Cilacap at the south coast of Central Java, and around the city of Medan in North Sumatra. These industries create a good number of job opportunities and revenue to the Government. Unfortunately, they also generate a great volume of industrial waste, which if mismanaged could exert envi ronmental pressures on the coastal region.

4.3 Manipulation of hvdroloqical cycles

Limited data on manipulation of hydrological cycles are available for the region. All major rivers draining the Central Plain of Thailand have dams built in the upper reaches for hydroelectric power generation as well as irrigation purposes. As a result of these, rice can now be grown twice a year instead of the normal once a year. On the other hand, salinity intrusion in soils has damaged orchards on both sides of two rivers, the Chao Phraya and Mae Klong. Damage ranged from reduction of productivity in most cases, to complete destruction of even the exceptionally tolerant coconut trees. Aside from this, some parts of the river banks in Bangkok draw up slightly salty artesian well waters. This, however, is not surprising in view of the fact that Bangkok is only slightly above sea level. The Mae Klong residents seem to suffer from the intrusion effect much more than the Chao Phraya residents. It was suggested that this may be attributed to the greater discharge of the latter river.

Similarly, there are eight major dams across the upper reaches of rivers in Malaysia, and more are planned. Besides these dams, there are tidal control gates built at the lower stretches of the rivers. The sharp decline in the salinity of immediate coastal waters when the gates are raised during periods of heavy rains, has been reported to bring about mortality in coastal shellfish beds and marine fish cultured in suspended cages.

4.4 Other land use practices

Deforestation is a widespread problem in the region, whether one is referring to a small territory 1ike Hong Kong or a large country 1i ke Thailand where only about 25% of its original forests remain. Large scale denudation of the land has resulted in erosion and sedimentation of coastal areas.

4.5 Disposal of contaminated sediments, mine tai1 inqs and sol id industrial wastes

There is very limited information on disposal of industrial wastes. The industrial sector of Hong Kong is reported to produce some 600 tonnes of industrial sludge per year. This, together with sewage, septic tank, agricultural waste and alum sludges (0.3 million m3 in 1983 and expected to increase to 0.5 million m3 in 1990) is dewatered and dumped in the open sea. Effects of sludge dumping on the marine environment have not been studied. Likewise, no assessment has been made on the impact of toxic, hazardous, difficult (THD) wastes which amounted to 29,838 tcnnes in 1984. These include alkali and acid waste, oil and oil-water emulsions, solvents, metal oxides, tannery 3rd cyanide waste among others. Over 95% of these wastes are diluted before being discharged into the sea through the sewer system of Victoria Harbour. Altogether, about 100 million m3 of materials and marine spoils generated from various development projects were dumped into the coastal waters of Hong Kong for the period 1981-1986. In 1980, four major open water dumping grounds for all marine spoils were selected to replace the 20 scattered marine dumping sites all over Hong Kong. The results of a single survey at one of these four major dumping sites showed normal benthic and fish communities at about a kilometer away from the site. With the exception of Hong Kong, mining is one of the major industries which contributes to the socio-economic development of many countries in the region. Consequently, considerable terrestrial mine tai 1 ings have been transported into the coastal zone. In the Philippines for instance, about 300,000 tonnes of mine tai 1 ings are generated daily from metal 1 ic mining firms alone. Of these, about 145,000 tonnes are dumped directly into the sea via pipe-line systems. Conceivably, the eventual settling of the sediment onto the seabed has in many places smothered pockets of coral reef. Studies on the effects of sedimentation in general on coral reefs (Yap & Gomez, 1985), provide useful base1 ine data on the more apparent effect of sediments and recovery of damaged reefs. The effects of the accompanying toxic ions in these tailings are less known. 4.6 Disposal of solid matter (litter) Solid waste, chiefly garbage, is commonly disposed of either by the sanitary land fill method or by incineration in many urban areas. However, as mentioned in the earlier sections, direct dumping of garbage in many rural as well as urban areas is widespread. While coastal land fills also release sediment and organic materials into the neighbouring waters, direct dumping of domestic refuse poses a greater impact. Littered coral reef areas near coastal settlements are a common sight in many places in the region (e.g. Ambon Bay, portions of the Straits of Malacca, various coastal areas in the Philippines). The increased use of plastic in recent years has consequently increased the load of non-degradable litter in the sea. This, more than any other refuse mat.eria1, presents a potential detrimental impact. It is very 1 i kely that sensitive benthic communities (e.g. coral and seagrass beds) may be smothered and the community structure disrupted. However, no such obvious impact attributed to smothering by refuse in particular, has been reported. In general, the large scale disposal of litter in the sea is not a common practice. Garbage dumping by ships, however, is not uncommon. The wastes often find their way to shores near shipping lanes. Singapore has very strict laws against littering and illegal dumping of waste. The country has an efficient system of solid waste disposal, 70% through incineration and 30% via sanitary landfill. The volume of floating refuse in Hong Kong is exceptionally high. Floating refuse scavenged from the sea increased from 3,279 tonnes in 1970 to 8,200 tonnes in 1983. In addition, a considerable amount (e.g. 1,026 tonnes in 1982) is collected from urban beaches. In terms of number of items and area covered, plastic materials form the main bulk (> 50%). Apart from being a nuisance which spoils the aesthetic value of the environment, floating refuse also reduces the amenity of swimming beaches and causes marine navigational hazards (particularly for hydrofoils which are abundant in Hong Kong). 4.7 Marine transport of oil and other hazardous substances Crude oi 1 amounting to about 3 mi 11 ion barrels is shipped through Southeast Asian waters daily via the Straits of Malacca, in addition to about 3.8 million barrels per day which leave this region through the South China Sea to Japan (Fig. 5) (Bi la1 , 1985). The Malacca Straits are dangerously shallow in certain stretches and deepwater channels are narrow. This in addition to its heavy traffic (Table 4) has resulted in several major accidents involving oi 1 spi 11s. Some of these are listed in Table 5. There is little information available on the effects of these oil spills on the marine environment. In Hong Kong, marine fish farming was seriously affected. In the incidents involving the Ap Lei Chau in 1973, the Oriental Financier in 1976 and the Adrian Maersk in 1977, cultured fish were killed or tainted resulting in the loss of over 273 tonnes and 540,000 fry. In the 1982 and 1985 spills, several swimming beaches on the south of Hong Kong Island were seriously contaminated and top layers of the beach sand had to be scooped off for disposal .

Table 4. Frequencies of tanker movements in Southeast Asia (Val enci a, 1981) . Destination Hypothetical Frequency (Route) Vessel Size

South Korea and Japan 200,000 DWT 984lyr (110.4 days) Japan ( Lombok-Makassar-Sulawes i VLCCs 1401yr (112.6 days) Sea-east or west of the Phi 1 ippines) Sul awesi Sea VLCCs + 25-30Iyr (1113.5 days) Tankers Port Dickson, Malaysia 90,000 DWT Singapore VLCCs 91Iyr (114 days) (Singapore-Straits) Various 15,356Iyr (I/ .O24 days or 1/34 min.)

The grounding of the Japanese super tanker Showa Maru in January 1975 in Singapore Strait, which is considered to be the largest oil spill incident in the region, caused extensive defol i ation and death of mangroves. Three years 1 ater, no sign of regeneration was reported (Soegiarto & Polunin, 1981). Similarly, the spill from the Diego Silang in the Malacca Straits in 1976 resulted in defoliation of mangrove trees mainly due to the smothering of the pneumatophores. Aside from these incidents, a greater volume of oil discharge comes from normal shipping operations 1 i ke tank-cleaning, drydocki ng, bunkering and cargo loading and unloading. Oil released during debal lasting operations is in the form of tar lumps and weathering produces tarry residues and tar balls. Bilal et a1, - < 0.1 million barrels per day (7 barrels = 1 metric ton) - 0.1-0.2 million barrels per day - 0.2-1.0 million barrels per day > 3 million barrels per day A Offshore production site Refinery

Fig. 5. Transport of crude oil in Southeast Asia (1975) (after Finn et al, 1979 in Bilal, 1985) Table 5. Oil spill incidents in Southest Asia*

Country Location Date Name of Ship Cause Quantity TYPe (tons)

Hong Kong - 1968 Columbia Trader Grounding heavy marine diesel - 1973 Ap Lei Chau - heavy marine diesel - 1973 Eastergate & Collision aviation fuel Circae - - 1974 Korea Hope Grounding aviation fuel Junk Bay - 1976 Oriental Finance Grounding - - 1977 Adrian Maersk Grounding bunker oil Repulse Bay - 1982 (burst pipe) Discharge fuel oil Repulse Bay - 1985 Frota Durban Grounding bunker oi 1

Indonesia Labon Besar Jut. 1987 Elhani Groundi ng Batu Berhanti Jut. 1987 Stolt Avance Grounding

Malaysia Singapore Straits Jan. 1975 Showa Maru Grounding - Singapore Straits Apr. 1975 Mysel la Groundi ng - Malacca Straits Jut. 1976 Diego Sitang Collision - Singapore Straits Oct. 1976 Citti di Savona Collision crude oi 1

Phi lippines Pasig River Aug. 1975 L-1909 Lusteveco Barge sinking fuel oil Manila Bay Vic. Aug. 1975 L-235 Lusteveco Grounding fuel oil Cavi te Off Escalante Pt. Oct. 1975 M/S Shotoku Maru Collision, fuel oil Negros Occ. Sinking Rosario, Cavite Apr. 1976 Filoil Refinery Accident sludge 01 1 Sasa, Davao Aug. 1976 Mobi Le Depot Leakage due to fuel oil broken pipeline San Fernando, Oct. 1976 LSCC Petrochem Groundi ng fuel oil La Union BRC Batangas Nov. 1976 M/T Raja Sulayman Leakage crude oi 1 Vic. Cape San Dec. 1976 M/S San Diamond Sinking fuel oi 1 Agust in Manila Bay Dec. 1976 M/V Gen Santos Sinking fuel. diesel oil

* Culled from country reports. For additional information, please consult Yap et at. 1988. Oi1 pollution and its control in the East Asian Seas region. Table 5. Oil spill incidents in Southest Asia * -- Location Date Have of Ship Cause Quantity (tons)

Hong Kong - 1968 Columbia Trader Grounding heavy marine diesel - 1973 Ap Lei Chau - heavy marine diesel - 1973 Eastergate & Collision aviation fuel Circae - - 1974 Korea Hope Grounding aviation fuel Junk Bay - 1976 Oriental Finance Grounding - - - 1977 Adrian Maersk Grounding bunker 01 1 Repulse Bay - 1982 (burst pipe) Discharge fuel oil Repulse Bay - 1985 Frota Durban Grounding bunker oi 1

Indonesia Labon Besar Jut. 1987 E Lhani Grounding Batu Berhanti Jut. 1987 Stolt Avance Grounding

Malaysia Singapore Straits Jan. 1975 Showa Maru Grounding - Singapore Straits Apr. 1975 Mysel la Grounding - Malacca Straits Jut. 1976 Diego Silang Collision - Singapore Straits Oct. 1976 Citti di Savona Collision crude oi 1

Phi lippines Pasig River Aug. 1975 L-1909 Lusteveco Barge sinking fuel oil Manila Bay Vic. Aug. 1975 L-235 Lusteveco Grounding fuel oil Cavi te Off Escalante Pt. Oct. 1975 MIS Shotoku Maru Collision, fuel oi 1 Negros Occ. Sinking Rosario, Cavite Apr. 1976 FiLoi 1 Refinery Accident sludge ci1 Sasa, Davao Aug. 1976 Mobi Le Depot Leakage due to fuel oil broken pipeline San Fernando, Oct. 1976 LSCO Petrochem Grounding fuel oi I La Union BRC Batangas Nov. 1976 M/T Raja Sulayman Leakage crude oi 1 Vic. Cape San Dec. 1976 MIS San Diamond Sinking fuel oil Agust in Mani La Bay Dec. 1976 MIV Gen Santos Sinking fuel. diesel oil

* Culled from country reports. For additional information, please consult Yap et al. 1988. Oil pollution and its control in the East Asian Seas region. w ..-F *G . $ ex 0 w3 www xu* m 1- w.5ww.-*xJ3 km> w4-1N-r- m mw<~mt_mCD 2; g,k z k$j kZ5' UE: 1-3: t-Â¥ >,EN 1- mmoomo t/1x:Ll-mm3

. . . ccv 3 3 U -0 (1982) reported some areas in the region that had quite significant s-ontamination by tarball s. Concentration of tarballs in Northern Luzon, Phi 1ippines was 0.630 kg/km2 and was as i-nuch as 1.6 kg/km2 northeast of this area in 197'3. As for Indonesia, there were reports of stranded farballs in two beaches, (i.e. Pulau Putri, 1970; and Pulau Tidung, 1972) in Kepulauan Seribu. Density af stranded tarballs could reach about 2,000 g/m . Stranded tarballs were also found on the south coast of Java and a few beach areas in Malaysia. Fig. 6 shows the distribution of oil lumps and transport of oil and surface currents in Southeast Asia.

Oostdam (1984) in a comparative survey of the degree of tar pollution in 265 beaches of the Indian Ocean* the South China Sea and the South Pacific Ocean reported tar concentrations found in the beaches of four countries in Southeast Asia. The mean values that he reported were: Indonesia: Sumatra, 0.7 Â 1.0 g/m and Java, 11.4 2 18.7 g/m; Malaysia, 125.1 + 129.4 g/m; Singapore, 10.0 Â 1.2 g/m; and Thailand, 17.8 Â 26.6 g/m.

contamination from the discharge of oily bilge waters and spillage of gasoline from large vessels and small craft used by fishermen is evident on an increasing scale ^'n various coastal waters.

Since 1984, concerted efforts were taken by the Malaysian and Singapore Governments to control pollution from vessels in the Strait of Johore. These have resulted ir. a decrease in the level of oil and grease in the narrow strait.

Accidents involving transport of toxic substances are uncommon. The only available information was reported from the Philippines. In December 1977, 350 tonnes of sulfuric acid were reported to have been lost at sea. In June 1978, 500 tonnes of caustic soda were spi 1led due to a sinking barge and in September of the same year, 20,000 bays of fertilizer were spilled from a vessel due to a typhoon.

4.8 Exploitation of non-livinq marine resources

Oi1 and qas

The South China Sea and the Indonesian waters can be said to be the center of activity for oi1 and gas exploration and exploitation in the EAS region. From the offshore wells the oil and gas are conveyed to shore-based terminals chiefly by seabed pipelines. Other areas where exploit ation is in progress on a smaller scale include the Gulf of Thailand, for nas, and the Palawan and Sulu Archipelago areas of the Phi 1ippine waters, for oi 1 . According to Ahmad (1988), oi 1 and gas production in 1986 totaled 2 mi11 ion bblsld. and 5 billion ft3/d respectively with 45% of these currently produced off shore.

Adequate precautions have been taken by the oil industry to prevent accidents such as blow-outs at the oil wells and leakages from the seabed pipelines.

Mining for tin is in progress in the sandy seabed of the Andaman Sea off Phuket Island, in the northern portion of the Straits of Malacca. Mining is carried out in the shal low coastal area by the use of dredges. Further south in the Straits of Malacca are potential areas with tin deposits, which may be 0 Few oil lumps o Many oil lumps - - J^ ,> Transport of oil (width indicates amount) - Average surface currents ww^ Border between currents

Fig. 6. Oil lumps, transport of oil and surface currents in South and East Asia (after Nasu et a1, 1975) exploited if environmental considerations are disregarded; the seabed here is chiefly soft mud, and any agitation may give rise to a considerable increase in the turbidity of the water.

Sand

In Phi 1ippine coastal areas, magnetite sand mining was carried out in the 1970s but the activity is now discontinued by law, in order to conserve recreational shorelines. However, mining for silica sand is still in progress in the Palawan area, but on a limited scale.

In Hong Kong waters, seabed mining for smd was also activity pursued in the 1970s, to cater for the building industry. The annual extraction of sand from the seabed was then in the region of 1,560,000 tonnes. This quantity has now declined to

Coral

fining of coral reefs used to be carried out in the 1970s, in the South China Sea off the east coast of peninsular Malaysia and in the Sulu Sea near Sabah. The calcareous skeletons of coral were used in the building industry. The activity, however, has been reduced due to the establ ishment of conservation programmes including marine reserves. There is no legislation yet out1awing coral mining in Malaysian waters outside of marine parks.

4.9 Exploitation of livinq marine resources

Traditional f ishinq

There is a general decline in fishery resources in the EAS region as a whole, mainly due to over- exploitation. This can be related to increasing populations in the area and human demands for food. The bulk of the fishery comes from the inshore coastal waters, within 50 km from shore. In the Malaysian sector of the Straits of Malacca the annual catch recorded in 1985 was about 327,000 tonnes compared to the potential yield of this area which is estimated to be only about 250,000 tonnes. On the contrary, in the South China Sea waters bordering Malaysia, about 246,000 tonnes of fish were caught in the same year, as against a potential yield of 690,000 tonnes, thereby indicating the greater potential for exploitation in this area. The major species exploited include the Indian mackerel (Rastrell iqer katiaqurta) , the cockle (Anadara qraflosa) , the anchovy (~ephorus sp.) and a variety of penaeid prawns. The main gear used in fishery exploitation in Malaysian waters are the otter trawl, the purse seine ard the drift gill net. The otter trawl, though acclaimed to be an efficient fishing gear, is also known to have damaging effects on the seabed marine ecosystem.

In the Loher Gulf of Thailand natural stocks of the short-necked clam (Pahia undulata) were exploited quite intensively. In recent years their stocks have shown a sharp decline believed to be due to the disturbance of the seabed by the destructive beam trawl. The annual fishery production in Thailand is about 2 million tonnes, but a significant amount of this comes from distant waters. This is owing to the virtual collapse of the fishery in the Thai waters as a result of over-f ishing, particularly by trawlers.

Indonesian waters have a1 so been over-expl oited, due to the tremendous demands for food by the large population of the country. Trawl fishing has been banned in Indonesian waters in recent years in an effort to bring about recovery of the resources. The annual catch of fish in Phi 1ippine waters was about 1.8 mi 11 ion tonnes in 1985. Here again the resources have been exploited to bring about significant declines. A major portion of the fish consumed in Pong Kong comes from the South China and East China Seas. The catch per unit effort as well as the demersal fish stocks in the northern shelf of the South China Sea have declined since 1975, due to over-f ishing. Within Hong Kong waters fishery product ion hay decl ined in the Tolo Harbour and Tolo Channel, probably due more to pollution.

Abusive fishing

Apart from the traditional methods of fishing, abusive fishing by the use of underwater explosives and poisons is carried out in many parts of the EAS region, particularly -in the waters of Indonesia, Malaysia, the Phi 1ippines and Thailand. Such practices are illegal and are under constant surveillance by enforcement offici a1 s. Underwater explosives are commonly used in coral beds, which have fairly heavy concentrations of fish and which cannot be exploited by nets.

Exploitation of aquarium fish

Marine aquarium fish are being exploited in several countries, particularly the Philippines, chiefly for export. In 1984 a catch of 0.4 tonnes of marine aquarium fish was recorded. The fish used to be collected in greater quantities in earlier years, by the use of sodium cyanide. This practice has now been discouraged, in view of poor export demands and the requirement by overseas importers that the fish be caught by non-harmful means.

Exoloitation of marine shells

Marine shells are being exploited in the Philippine waters, but due to depletion of stocks, there has been a steady decline in their exploitation. In 1983 about 2 tonnes of shells and byproducts were exported. The ban on the collection of certain species has not prevented unscrupulous elements from exploiting them. The shellcraft industry has also been developing in other countries in the region, and production is on the increase.

Coastal manculture

The decline in fish resources generally experienced in the EAS region has triggered the development and expansion of coastal maricul ture.

Lockles (Anadara qranosa) are being farmed in about 5,000 ha of the codstal mudflats in the Straits of Malacca, bordering the west coast of peninsular Malaysia. The annual production of cockles from these mudflats, as recorded in 1985, was about 44,800 tonnes (Malaysia, 1986b). There are moves to expand this activity further to other coastal mudflats in the region. This bivalve is known to thrive well in waters carrying high organic loads.

Coastal mariculture is also growing in importance in the Straits of Malacca. The major species cultured are the sea bass (Lates calcarifer), the grouper (Eoineohelus tauvim and the tiger prawn (Penaeus monodcn) in ponds and cages; and the green mussel (Perna viridis) on rafts. The annual production of fish and crustaceans from coastal mariculture, as recorded in 1985, was about 600 tonnes (Malaysia, 1986b).

Similarly, mariculture is rapidly expanding in the waters of Indonesia, Thailand, the Philippines and Hong Kong, partly to off-set the decline in the natural stocks. In Thailand, the 1981 mariculture production for several bivalves was as follows: blood clams (Anadara) - 77,735 tonnes, green mussels (Perna) - 129,633 tonnes, and oysters (Crassostrea spp .) - 60,105 tonnes (Hungspreugs, pen. comm. ) .

5. BIOLOGICAL EFFECTS

The most pronounced biological effects in the region are those resulting from organic pol lution and eutrophication. Biological effects resulting from other types of pollution are much less obvious.

5.1 Eutrophication and associated phenomena

Eutrophication in various coastal waters receiving high organic inputs from sewage is common in the region. Substantial information on the biological effects of organic enrichment is available from a series of studies in Hong Kong. It has been shown that organic loading has caused an increase in the standing crop of phytoplankton in Victoria Harbour (Thompson & Ho, 1981). In Tolo Harbour additional changes in species composition of the phytoplankton community, with diatoms being gradually replaced by dinoflagellates, are also noted.

Malaysia reported nutrient enrichment in some parts of the Straits of Malacca (around Penang Island and in Johore) and off the coast of Sabah that has given rise to eutrophication of waters and high BOD (Jothy, 1984a). However, in other offshore areas of the South China Sea the phosphate levels were low, e.gi Trengganu surface average 2.17 mg/m3 (Law & Rashid, 1986), off Kuantan 5.58 mg/m (Law & Shai k, 1987). Organic load from sewage in the northern part of the Straits is believed to have given rise to considerable levels of microbial contamination in shellfish.

Both toxic and non-toxic red tides have been reported in the Philippines (Pvrodinium bahamenx var. compressa) , Thai land (Trichodesmium erythream, Nocti luca mi1 iaris, Ceratium furca and Gonvaulax spp.) , Indonesia (Nocti luca mi1 iaris) , Ma1 aysia (Nocti 1uca mi1 iari s, Pvrodinium bahamensg var. compressa) and Hong Kong a total of 18 sppcies, including Gymnodin~umna~asakiense, Nocti luca mi1 i aris, Cerati um furca, and Prorocentrum micans) . Several other red t ;de phenomena have been reported from Kau Bay, Halmahera, Ambon Bay, and Jakarta Bay. Except for Jakarta Bay, the cause of ped tide blooms are not yet scientifically substantiated. Nocti luca miliaris blooms occur in Jakarta Bay periodical ly due to eutrophication of the coastal waters (Adnan, 1984a; Praseno & Adnan, 1978). The bloom normal ly occurs in September or October, coinciding with the first period of the season's heavy rain. It is a1 so noted that the occurrences of red tide are more frequent in Malaysia, the Philippines, Thailand and Hong Kong in recent years.

Fish ki11s caused by red tides have also been recorded in the region. Farmed fish which are confined in cages as we1 1 as juvenile fish, are most seriously affected (Suvapeepun et a1, 1984). For example, from 1980 to 1984 a total of 11 fish ki11s in maricul ture areas in Hong Kong were caused by red tides with a total loss of 56 tonnes of cultured fish. It has also been a1 leged that the Noctiluca bloom in 1982 prevented settl ing of green mussels on poles in the upper Gulf of Thai land. Red tide toxins accumulated by she1 lfish are a1 so we1 1 documented in the region, (the resulting pub1 ic heal th hazard is discussed in section 5.Z). The unusual ly frequent red tide blooms in Thai land in 1983, however, were not associated with any increase in nitrogen and phosphorus for that particular year in the general area. Although there is no direct evidence to attribute the occurrences of red tides to eutrophication in the region, there appears to be a correlation between the progressive increase in the frequency of red tide occurrences in Hong Kong since 1977 (Table 6) and an increase Table 6. Number of red tides and fish ki11 s due to red tides, algal blooms and oxygen depletions in Tolo Harbour, Hong Kong (Wu, 1987). -- -- No. of fish kill due to Year No. of red tides red tides, algal blooms and oxygen depletions

in the level of eutrophication. The frequency of occurrence is also higher in eutrophic waters compared with that in open clean waters, and the causative species of red tides have become more diversified in recent years (Wong & Nu, 1986) . The most pronounced biological effects of eutrophication are probably those on benthic communities. Detailed studies conducted in 1978-1980 in Hong hong clearly showed spatial changes in the epi-benthic community structure along the organic pollution gradient. The decrease in community diversity as well as abundance and dominance of predatory gastropod-? a1 ong the gradient a1 so reflect changes in trophic structure brought about by organic pollution. In contrast to the situation in Manila Bay, however, no significant change in th? percentage of deposit feeders was found. Likewise, the species composition and trophic structure of the fish community changed in relation to the pollution gradient. In the harbour where organic pollution is severe, summer mortality of fish and benthos due to oxygen depletion followed by winter recovery becomes a regular phenomenon, and it was postulated that such a phenomenon may be characteristic in subtropical benthic systems subject to high levels of organic pollution. It was also noted that the time required for recovery after complete defaunation was much shorter when compared with thut in temperate regions (Wu, 1982) . Other studies in 1976 and 1979 on the benthic community in Victoria Harbour indicated no significant evidence of pollution, despite the heavy pollution load. It was concluded that the pollution impact was fairly localized due mainly to good flushing rates in the harbour (Shin & Thompson, 1982; Thompson & Shin, 1983). 5.2 Public health effects

5.2.1 Paralytic shellfish poisoninq (PSP)

The occurrences of toxic red tide blooms in the region, described in section 5.1 above, have led to several documented PSP cases in the region.

A few isolated cases of red tide have also been reported from Indonesia (Adnan, 1984a and 1984b). An incident of red tide poisoning through the ingestion of clupied fish, Sardinella spp. and Selar~idesle~:olepis, was reported in two fishing villages in East Flores, East Nusa Tenggara province in November 1983. In that incident four people died, and some 240 were taken ill after consuming their daily catch,

The first recorded PSP outbreak in Thailand occurred in May 1983, in which 63 people were affected (with one fatal case) after consuming green mussels (Perna viridis) contaminated by dinofl age1 lates (Gonyautax sp.) . In this incident, PSP toxin was detected in wssels and oysters. The highest level recorded was 12,057 pg/lOOg in one mussel sample (Saitanu & Tamiyavanish, 1984).

Toxic red tides caused by Pyrodini um bahamense var. compressa have occurred several times in the inshore waters of the west coast of Sabah and Brunei Bay since 1976 {n which PSP and fatal cases were reported (Jothy,1984b). A bloom of this species occurred and extended for some 3 months during the second half of 1983 in the Philippines (Estudillo & Gonzales, 1984). In this incident, some 24 people died and many more suffered from PSP symptoms after consuming seafood exposed to this toxic red tide.

Although there has been no documented case of PSP in Hong Kong, toxic species (e.g. Gymnodinium naqasakiense) have been found in these areas. The potential risk of FSP resulting from the ingestion of she1 lfish, therefore, should not be overlooked.

5.2.2 Pathoqens in water and shellfish

Concentrations of coliform in a number of locations in the region exceed national standards, indicating the potential risk of exposure to human pathogens and consequent disease transmission. However, records of human disease associated with swimming in polluted waters are lacking for the region.

A drastic inc:ease in coliform count was noted in Manila Bay from 1983 to 1985 (Table 7) . Col iform counts in a1 1 beach resorts exceeded the maximum a1 lowable total of 1000 MPNI100 ml for recreational waters. Coliform counts in other areas of the bay also exceeded the maximum of 5000 MPN/100 ml for waters for aquaculture.

In Hong Kong, recent surveys found that five swimming beaches exceeded the standard for recreational waters (Wu, 1987). Coliform levels as high as 26,000 MPN1100 m1 were obtained in some samples. In the early 1980s, 2 of the 41 gazetted swimming beaches were already closed to the public because the bacterial counts exceeded the local standard (i.e. running median of five consecutive samples not exceeding 1000 E. col ill00 ml) and in 1987, a total of 4 beaches were closed for swimming because the contamination exceeded the above standard. Likewi se, an increase in faecal pol lution was evident in Tolo Harbour and Victoria Harbour, as reflected by a progressive increase in the levels of total col iforms and faecal coli forms from 1973 to 1983 (Table 8). A iMde area with levels of faecal coliform exceeding 1000 MPN/ 100 ml was ident if ied in Victori a Harbour. Faecal col ifom levels reached 10 - lo6 in areas with poor water circulation in the harbour. Table 7. Col iform counts in selected coastal areas in the Philippines (MPN1100 ml )

Location 1977 1978 1979 1980 1981 1982 1983 1984 1985

I. Manila Bay

1. Punta Grande

2. Villa Susana

3. Star Fish

4. San Agustin

5. San Isidro

6. Villamar

7. Lido

8. Mabuhay

9. Future Seaside of MCCRRP

10. Baclaran

11. Seaside of MCCRRP (CDCP)

12. Northwest of CCP

13. South Breakwater

14. Holiday

15. Garden Coast

16. Pasig River Outlet 17. Luneta Grandstand ------77926 297641 18. Vitas Navotas ------512120

11. 19. Davao City ------2002

111.20. Cebu Harbour 18139 ------Table 8. A comparison of yearly median values of total coliforms and faecal coliforms in Victoria Harbour and Tolo Harbour stations over the period 1973-1983, no./lOO ml (Wu, 1987).

pp - - - -- Total col iforms Faecal col iforms

Victoria Harbour Tolo Harbour Victoria Harbour Tolo Harbour

In coastal waters around Jakarta, pathogens have been reported in edible shellfish and fish. Similarly, high numbers of faecal coliform were found in shellfish beds contaminated by sewage pollution in the Straits of Malacca. Elevated col iform levels in oysters and mussels in the Gulf of Thai land were reported particularly during the high flow season resulting in low salinity of coastal waters. Bacteria examined were Vibrio parahaemol vticus, y. cholerae and Salmonel la sp. Studies conducted on the Pacific oyster Crassostrea qiqas in Deep Bay, Hong Kong, in 1973 showed that the level of contamination increased markedly with the onset of the summer rains in June to levels of 4.7-12 L. mlmg tissuewhich is higher than the shellfish standard of 2 E. mlmg. (Leung et al, 1975). This indicates that the potential risk of human pathogen transmission by consumption of local oysters is high. In addition, studies in 1972 revealed a range of pathogenic bacteria (e.g. Salmonel la spp., Shiqel la boydi i and S. flexneri) that were found in clams (Katelysia sp. and Venerupis sp.) collected from Tolo Harbour (Kueh & Trott , 1972). More recent studies in 1985 showed that the levels of total coliform and faecal coliform in clams (Tapes varieqatus) and mussels (Perna viridis) collected from Tolo Harbour were generally high, reaching up to 11,000 total col iformlg and 370 faecal col iformlg (Ni & Huang, 1985). An epidemic outbreak of hepatitis associated with the consumption of shellfish occurred in Hong Kong in early 1988. Within the first three months of the year, 1396 cases of hepatitis had been reported, in which 591 cases were confirmed to be hepatitis A and 76 cases hepatitis B. More than half of the victims consumed local shellfish shortly before the infection, indicating that local shellfish are grossly polluted and served as the main carrier of the hepatitis virus in this epidemic outbreak. A survey of pathogenic bacteria in shellfish in Jakarta Bay indicated contamination of Anadara (cockle) and Crassostrea (oyster) by Salmonel 14, Shi qel 1 a, --E. col i and Staphvlococcus (Thayib et a1, 1977) . 5.2.3 Others High concentrations of Cd and PCB have been identified in oysters, mussels and seafood samples in Hong Kong (for levels, Phillips, 1982, 1985; Phillips et a1, 1982), suggesting a possible risk of exposure to organochlorines and Cd tor the Hong Kong population. 5.3 Damaged habitats and resources and their potential for recovery and rehabi 1 itation During the drought and the low flow in the rivers of Thailand in 1972, sugar factories along a river bank discharged untreated sugar waste directly into the river, causing extensive damage to the tube shell beds and cockle farms near the river mouth. Recovery was noted 2 years later and now the cockles and the tube shells are growing again, though recovery is still not quite complete for the cock1 es . In Hong Kong, it has been shown that the recovery of the epi-benthic community , after pol lution-induced defamation, takes a much shorter time when compared with that in temperate regions. Complete recovery of inter-tidal communities on reclaimed shoreline, however, takes some 8 years. The transformation of the once heavily pol luted Singapore river into a recreationltourist centre (discussed in the previous chapter) is perhaps the most remarkable example of recovery of a damaged habitat in the region. Other encouraging signs are the effecti vness of pol 1 ution control measures evidenced for instance by the decrease of oil ?ollution in Johore Strait, coupled with advances in treatment technology for palm oil and rubber effluents in Malaysia. These developments contribute to reduction of the pollution load in coastal waters. Rehabilitation of mangrove areas has been taking place in the region !n recent years (e.g. central Phi l ippines) . Damaged coral reefs are generally known to recover slowly, especially where the stress is caused by human activities such as dynamite fishing (Alcala & Gomez, 1979). Recent studies on the recovery of natural damage as caused by a storm indicate that the recovery time may be considerably shorter (Alcala et a1, 1986). Some efforts have been taken to rehabilitate and preserlre coral reefs in the region through the establishment of marine reserves in Indonesia, Malaysia, Thailand and the Phi 1 ippines (Gomez et a1, 1984) (Table 9). Significant increases in the standing stock of fish have been noted where protection has been effective (e.g. Sumilon, Philippines). There are also plans for establishing similar reserves in Singapore. In addition some studies on coral transplantation and recolonization of damaged reefs have been initiated in the Philippines. The development of artificial reefs in Malaysian coastal waters to increase fish production is being undertaken extensively both in the Ma1 acca Straits and in the South China Sea. Similar developments are also taking place in various localities in the Philippines. On the whole, results have been yery Table 9. Marine parks and sites of special scientific interest - - Country/Existing park Projects/Recommended areas

A. ASEAN Countries*

INDONESIA

- Komodo Is1and Game Reserve - Bali Barat - Ujung Kulon National Park - Teluk Sarera marine area - Pulau Pombo Marine Park - Pulau Kasa Marine Park - Banda (1972) - Seribu Islands - South of Moyo Island - Karimun, Java Island - Bunaken Manade Tua - Maumere Bay

MALAYS IA

- Tunku Abdul Rahman National Park, - Semporna Marine National Sabah (1974) Park, Sabah - Turtle Islands National Park, - Pulau Redang Sabah (1977) (South China Sea off Trengganu) - Pulau Tiga National Park, Sabah (1978) - The Paya Group of islands - Klias Peninsula National Park (Straits of Ma1 acca off Kedah) - The Tioman Group of islands (South China Sea off Johore) - The Rawa Group of islands (South China Sea off Johore) - The Tinggi Group of islands (South China Sea off Johore) - The Perhentian Group of islands (South China Sea off Trengganu) - Pulau Kapas (South China Sea off Trengganu) - Pulau Tenggol (South China Sea off Trengganu)

PHILIPPINES

- Hundred Islands National Park, - Apo Reef Marine Park, Mindoro Luzon (1940) - Manila Bay Beach Resort - Sombrero Island, Batangas National Park, Luzon (1945) - Guindulman, Bohoi - Agoo-Damortis Shore and - Bal icasag, Bohol Terntori a1 Waters, Luzon (1962) - Honda Bay, Palawan - Cagayan Island Marine Sanctuary (1970)

* Gomez et a1, 1984. In the case of Indonesia, additional marine conservation areas were provided by the Ministry of State for Population and the Environment (1988) while for Malaysia, Mr. Jothy provided additional recommended areas. Table 9. (Cont'd) Country/Existing park Projects/Recomnended areas

PHILIPPINES (cont'd) - Camiguin Island Marine Sanctuary (1970) - Gui uan Peninsula Marine Sanctuary, Samar (1970) - Ma1 ampaya Sound Marine Sanctuary Pal awan (1970) - Nasugbu Marine Sanctuary, Batangas (1970) - Pangui 1 Bay Marine Sanctuary, Mindanao (1970) - Pol i1 lo Islands Marine Sanctuary (1970) - Turtle Islands Marine Sanctuary, Sulu (1970) - Southern Luzon Marine Biological Station - Macajalar Bay Marine Biological Station - Puerto Galera Marine Biological Station and Reserve, Mindoro - Matabungkay Bay, Luzon - Sumi lon Island, Eastern Cebu (1974) SINGAPORE - none - none THAI LAND

- Koh Tarutao National Park off - Phi Phi Islands Satun (1974) - Similan Island Marine Park, Andaman Sea - Surin Island Marine Park, Andaman Sea - Nai Yang National Park B. HONG KONG - Mai Po Marshes - Tsim Bei Tsui - Pak Nai - Lung Kwu Chau, Tree Island & Sha Chau - Tai Tam Harbour (Inner Bay) - Tai Long Bay - Lai Chi Wo Beach - A Chau promising and widespread reef development in the region is anticipated. While some of these artif ici a1 structures are not permanent, continuous efforts by coastal inhabitants to maintain or replace them may have long term oenefits.

5.4 Accidents and episodic events

Information on natural catastrophies in the region is available almost exclusively for the Philippines, and to a much lesser extent, for Thailand.

In the Philippines, the natural (-vents that have caused some impact on coastal areas are volcanic eruptions, storm surges and tsunami. Major eruptions of Mount Mayon in 1984 resulted in mudflows into the sea on the southeastern coast of Luzon. A total volume of 1,389,740 m3 of mud was reported to have reached the sea, the impact of which was not measured. The only available information indicates that leachates of mud contained mean concentrations of 59.1 ppm chloride, 281.3 ppm sulfate and 93.6 ppm sulphur.

Several tsunami have been recorded in the past century, with the most destructive one occurring in 1976. A violent earthquake (approx. magnitude 8) originating beneath the Moro Gulf south of Mindanao spawned a tsunami that affected 700 km of coast1ine. On shore, wave heights ranged from 3 m to a maximum of 9 m and water reached up to 2 km in1and. About 8,000 persons died or were missing after the catastrophe with another 10,000 injured and about 90,000 rendered homeless. The most dramatic effect was on human settlements. Much beach and mangrove vegetation as well as marine life along the coast was also adversely affected. No assessment was made of the impact on marine communities.

Storm surges are somewhat more common than tsunamis, even though they are often mistaken for the latter. Although the effect may be similar, they are of entirely different origin. The piling up of water is brought about by storms or wind forcing up shallow bays. In the Philippines, typhoons in 1897, 1908, 1912, 1970 and 1975, among others, have been known to cause storm surges. In the last occurrence, water levels reached a height of 2.4 m on shore and more than 100 houses were washed out and ether buildings damaged.

In Thailand, a series of strong depressions occurred in close succession in October 1983 which resulted in the flooding of the low-lying areas in many parts of the country for more then a month. Fortunately, there was no subsequent epidemic outbreak.

In Hong Kong an accidental oil spill in 1973 caused severe mortalities of bivalves , gastropods, sipunc-~l id5 and crabs, but no great reduction of natural populations was found for most of the species except for the gastropods Monodonta --abic and Nerita albicilia. A total kill of the meiofauna on the affected sandy beach was also found (Wormold, 1976; Stirling, 1977; Spooner, 1977).

Results of investigations after another accidental spill in Hong Kong in 1985 also showed that the effects of the oil spi 11 were minimal (Shin, 1986). The total hydrocarbon content of water and sediment in the most affected areas decreased rapidly from 2.5 to 0.5 mg/1 and 50 to 25 mglkg respectively 20 days after the spi 11, and returned to background levels at the end of the 150 days study period. No reduction in species, number of individuals and species diversity was found on rocky shore, soft bottom and in plankton communities in the affected area, except for severe mart-a1 ity of the rocky shore gastropod, bnodonta austral is , immediately after the spill. 6. PREVENTION AND CONTROL STRATEGIES The commercialization and industrialization of coastal areas usually go hand in hand with the growth of slums. Unless tackled in time, the slum dwellings degenerate and become major sources of pollution and pub1 ic health hazards because sol id and 1 iquid waste reception faci 1i ties cannot cope with the demands of the new soc iety . Slum formation is inevitable in any country undergoing rapid urbanization. It call s for much effort to establ i sh a network of sewers, drains, etc., and proper waste collection and treatment facilities. Provision of these facilities is essential as pollution control l&ws cannot be enforced without them. Thus prevention and control of marine pollution must be carried out within an integrated approach.

At. the national level, marine pol lution control strategies through land use regulations are currently practised in the region at various degrees of effectiveness. Most countries in the region use environmental impact assessment (EIA) as a tool in their planning process. These include Indonesia, Malaysia, the Philippines, Thailand and Hong Kong. In Singapore, although EIA is not required by law, it is still done for large projects, 1 ike petrochemical plants. Otherwise, the control on environmental pol 1 ution is done through a thorough vetting process where all relevant authorities must endorse the project oefore it can proceed. Zoning or segregation of incompatible development is necessary to try and balance the need for development and protection of the environment. In the Philippines, there are requlations to prevent the location of industries in highly urbanized areas, e.g., industries to be located outside the 50 km radius of Manila City Hall. In Singapore, there is a buffer zone of 100 m between the residential estates and light industries. Heavy and more polluting ones must be sited in specialized industrial parks. Industries are not a1 lowed to discharge effluents into watercourses without specific approval from the Environment Authority. Indonesia's transmigration policy has succeeded in relieving over-congested coastal areas and provided homes for the poor, by moving excess population to less populated and resource-rich areas. The agency responsible for coordinating environmental matters in Indonesia is the Office of the State Minister for Population and the Environment (KLH). The national themes of "The Environmental Principles of National Development" and "Development Without Destruction" are well adopted by decision makers, planners and environmental i sts in Indonesia. Priority areas of concern have been identified, e*g., - problems related to forest utilization - problems related to human settlement - problems re1 ated to marine pol luti on The KLH function now is much broadsr in scope. It coordinates national efforts on environmental matters, including drafting of laws and regulations and establishing environmental standards. In order to be effective, the KLH has to be supported by many government agencies, research institutions, universities and many national committees dealing with the envirormert. One such committee is the National Committee on Marine and Coastal Environments, One of the Functions of this cornmi ttee is to prepare rules and regul at i ons on the development andmanagement of marine and coastal areas, monitor pol lution and give advice to the KLH to take the necessary action on marine environmental protection. The conservation and protection of natural resources and the environment 1s coordinated by the Directorate -General of Forest Protection and Nature Conservation of the Department of Forestry. Its responsibilities also include the coastal environment (coral reefs, mangroves j set aside as conservation areas and the development of the marine parks system. The Centre of Oceano.logica1 Research and Development (CORD) of the Indonesian Institute of Sciences is the lead institution for research and monitoring of marine pollution. This centre plans to establish 22 monitoring stations located -in key sites in Indonesian waters. Many maieine areas have beei identified as national parks (Table 9) for the protection and conservation of critical marine ecosystems in the Asean region. Of these, Koh Tarutao National Park is also designated as an Asean Heritage Park. in Hong Kong, certain habitats 1 i ke mangrove areas are classified as "Site of Special Scientific Interest" for a higher degree of protection. In the Philippines, the status of many parks is unknown. However there is a growing awareness of the importance of marine parks and reserves, particularly for recreation and as replenishment areas for fisheries. In Malaysia, a total of 23 coastal marine locations have been gazetted as parks or fisheries prohibited areas (Malaysia, 1974, 1985). In order to ensure that natural ecosystems will be conserved, a number of coastal nature reserves have been establ i shed in Indonesia. Currently, the Indonesian Government is exploring the possi bi 1 ity of increasing nature conservation areas, from the present 8 mill ion to 10 million hectares by 1990, including a marine parks and reserves system. Pollution control at source is effected through setting of standards, rules and regulations and strict enforcement. Water quality standards have been set up in most EAS countries. Thailand's hater qua1 ity standards will be ready for implementation soon. Polluters are required to install effective pollution control facilities. Effluent discharge has to comply with Trade Effluent Standards. In Singapore, where industries discharge effluents exceeding the limits for discharge into public sewers, a levy is charged based on the concentration of the pollutants in the effluent. For direct discharge into watercourses, strict compliance with effluent standards is required. In the Philippines, a permit system has been instituted with corresponding penal provisions. In Malaysia, standards of effluent discharge are governed by the fol lowing regulations: Environmental Qual i ty (Sewage and Industrial Effluents) Regulations, 1979; Environmental Qual ity (Clean Air) Regulations, 1978; Environmental Qua? i ty (Prescribed Premises) (Crude Palm-011) Regulations, 1977; Environmental Qua1 i ty (Prescribed Premises) (Raw Natural Rubber) Regulations, 1978: and Environmental Qual i ty (Control of Lead Concentration in Motor Gas01 i ne) Regul at i ons , 1985. Effective pollution control strategies need strict compliance with environmental laws. This ,ieeds a strong political will to implement as the tendency is to favour development rather than environment. Environmental infrastructures like sewage treatment works are costly, and it is easier to spend the money on creating jobs than protecting the environment. In some cases there may be a need to take unpopular decisions like resettlement and removal of the sources of pol lution, e.g., re-si te pol luting industries away from the coastal areas or resettle squatter colonies into proper premises. This has been done in Singapore and is planned for implementation in Hong Kung and Malaysia. Besides the above measures, Indonesia, Malaysia, Singapore, the Philippines and Hong Kong have oil spill contingency plans. Thai land is drawing up its national oil spill contingency plan although the oil companies in Thailand already have a shared oil spill contingency plan. To sustain long term prevention and control, effectiveness depends on the environmental awareness of the people in the region. Envi ronmental education is therefore essenti a1 in maintaining a heal thy marine environment. Environmental education and awareness have been accorded top priority in the EAS region and are actively being pursued by Indonesia, Ma1 aysi a, the Phi 1 ippines, Singapore, Thai 1 and and Hong Kong. As pollution of the marine environment is not constrained by national boundaries, regional co-operation to sustain the health of the marine environment is very important.. Regional co-operation in prevention of accidents and marine pollution has been successfully implemented in the EAS region. Examples of this i nclude

1. Traffic Separation Scheme in the Straits of Malacca and Singapore. 2. Tripartite Agreement to Combat Oi 1 Spills in the Straits of Malacca and Singapore. 3. Tiered Area Oil Spill Response Capability Plan. 4. ASEAN Oil Spill Contingency Draft Plan. 5. ASCOPE Plan for the Control and Mitigation of Oil Pollution. 6. Regional Plan to Combat Oil in the Straits of Lombok/Makasar and the Celebes (Su 1 awes i ) Sea. Since the Traffic Seoaration Scheme was imolemented there has been no major accident in the Straits of Malacca, the last being the Diego Silang incident in 1976. The regional exchange of information is now being increasingly encouraged in an effort to prevent environmental disasters. In addition to the above, EAS countries are signatories to a number of international conventions related to the marine environment as shown in Table 10.

7. TRENDS AND FORECASTS

By the end of the Twentieth Century, 15 of the world's 25 most populous cities will be found in Asia. Of these 15 cities in Asia, 13 will be situated in coastal areas, -each with a population of more than 10 million people. The waste from such human settlements and the associated economic activity is enormous and in many of the cities, the waste enters raw into the coastal waters. It can also be anticipated that increasing ship traffic will result in further contamination of coastal waters, whether from oil, hazardous chemicals, or litter. The countries in the EAS region are mainly coastal states. Indonesia and the Philippines comprise mainly of islands and it can be assumed that virtually the entire population in these countries has an impact on the marine environment in the region. The trend for an increasing population is sti 11 forecast by the World Bank. A comparison of the population in 1985 and the projections for the year 200p showed the following: Table 10. International Conventions UN Convention on Law of the Sea Brunei, Indonesia, Ma1 aysi a Philippines, Singapore International Convention relating to Singapore Limitation of Liability of Owners of Sea-going Ships Convention on the International Indonesia, Malaysia, Philippines Maritime Organization (IMO) Singapore, Thai 1 and Convention on Facilitation of Singapore International Maritime Traffic International Convention for the Phi 1 ippines, Singapore Safety of Life at Sea International Convention on Philippines, Singapore Loads Lines Agreement on the International Singapore Association of Lighthouse Authorities (IALA) Convention on the International Malaysia, Singapore Hydrographic Organization Protocol of Agreement to the Singapore International Convention of 1924 for the Unification of certain Rules of Law relating to Bills of Lading Agreement for the Facilitation of Si ngapore Search for Ships in Distress and Rescue of Survivors of Ship Accidents Convention on the International Malaysia, Singapore Regulations for Prevention of Collisions at Sea Convention on International Maritime Si ngapore Sate1 1 i te Organization International Convention on Civil Indonesia, Hong Kong, Singapore Liability for Oil Pollution Damage Protocol to the International Singapore Convention on Civil Liability for Oi 1 Pol 1 ut i on Damage Convention on the Continental Shelf Malaysia, Thailand Convention on the High Seas Indonesia, Malaysia, Thai land Convention on International Trade Indonesia, Malaysia, Philippines in Endangered Species of Wild Singapore, Thai 1 and, Hong Kong Fauna and Flora 2000 (million) I ndones i a Malaysia Phi 1 ippines Si ngapore Thai 1 and TOTAL

(From World Resources Institute and lnterndtional Institute for Environment and Development, 1986)

In the ASEAN countries alone, the population is expected to -increase by 27% over a 15-year period. This would certainly increase pol lution stress and pressures from exploitation of resources of the marine environment.

Marine water qual ity in Hong Kong (1985 population: 5.5 mil 1 ion) has been deteriorating over the past 10-15 years . Even with the construction of sewage treatment plants, there was no significant improvement. The emphasis on environmental improvement is expected to lead to some amelioration. There are plans to move polluting farms and industries away from coastal areas which should lead to a general improvement in the marine environment. Malaysia's success in controlling palm oil effluent discharges has reduced the BOD entering the marine environment from 202,000 tonnes in 1980 to 148,000 tonnes in 1985. Deforestation and earthworks in the country have increased soil erosion causing 26 mi 11 ion tonnes of surface soi 1 to enter the Straits of Ma1 acca annually. However, with commitment from the highest government levels to improve the environment, it is expected that the degradation of the marine environment wi 11 be checked. An example of a positive development is the establishment of artificial reefs in Malaysian coastal waters which is expected to generate increased biological productivity in the years to come (Jothy, 1986). Utilization of resources is still proceeding at a rate beyond natural replenishment in the Philippines. Over a period of 70 years, mangrove cover decreased by 75%. There was also a decline in the demersal fisheries standing stock by 3% a year and a decline in the quality and quantity of coral reefs and seashell resources. Concentration of trace metals in Manila Bay and areas affected by mine tailings has been increasing. Singapore's marine water quality has been improving over the past 10 years. Most areas are expected to maintain their present level of cleanliness except for the Serangoon River mouth where a significant improvement in water qual ity isnot expected until late 1989 when pig farms will be removed.

In Thai land, it has been reported that natural resources, 1 ike forest cover and fish, havr decreased in quantity. However, it was also noted that artificially introduced c ontaminants have also decreased. The qual ity of fresh water has improved but this cannot be said of coastal areas where tourist developm~nt is taking place. Much of the pollution in these areas is caused by back-yard lw ¥sir and migrant workers flocking to these new development awas in se+r b n' e livelihood. Whi 1st there appears to be an increasing awareness of the urgent need to control marine pollution, the cost to effectively implement such a programme is very high. On the other hand, the economics of not doing so could be worse. This needs a strong commitment from political leaders. A concrete step in this direction is the Jakarta Declaration of 1987 where the Environmental Ministers of ASEAN adopted a resolution on sustainable development. A start has already been made in a1 1 EAS countries but more effort is needed to push forward the task of protecting the health of the marine environment. Climatic change effects There is limited information available on the effects of climatic change in the region. Available data are presented below. Annual mean air temperature readings in Hong Kong for the period 1884-1986 exhibit an increasing trend (Fig. 7) which is more pronounced during the period 1950-1960. No obvious trend is observed in mean sea temperature readings at Waglan Island, Hong Kong for the period 1958-1986 (Fig. 8) and in annual mean sea level at North Point, Hong Kong for the period 1977-1985 (Fig. 9). Mean maximum ai r temperatures measured at a meteor01 ogi cal stat ion (Bayan Lepas) in peninsular Malaysia indicate an increase of 0.5OC maximum air temperature, over a 50 year period (1935-1985) (Malaysian Meteorological Service, pers . comrn. ) . An analysis of 80-year mean sea level (MSL) data at three tide stations in the Philippines showed no discernible trend in Cebu (Fig. 10) and increasing trends in Manila (Fig. 11) and Davao (Fig. 12). The MSL increase in Davao is noted at approximately 15 cm for a 30-year period while in Manila, an increase of about 2 cm per year is noted for the period 1965-1985. The variation was attributed to development activities such as reclamation, fishpond construction, and coastal subsidence due to over-abstraction of groundwater. Si 1 tation of the waterways is also a possible contributing factor to MSL variation. Mean air temperature readings in Baguio, Phi 1 ippines show an increasing trend (Fig. 13). Temperature readings in Mani 1 a (Manila International Airport), however, while exhibiting a progressive increase for the period 1950-1980, show a decline commencing on the year 1981 (Fig. 14). On a national perspective, loss of vegetative cover is one factor identified as influencing temperature variation. Mean sea level data generated over a 41-year period from 29 stations in the Gulf of Thailand exhibit numerous fluctuations but no trend is readily recognized (Siripong, 1985). Three stations near Bangkok, however, show a slight rise in MSL. Bangkok which is about 2 m above MSL is believed to be "sinking" as a result of heavy groundwater abstraction in several of the city's suburbs. The impact of climatic change in the region cannot be assessed at this time. A separate study will address this question.

ECONOMICS An in-depth discussion on the economic implications of environmental impact the EAS region is not possible at this juncture. Environmental issues that may expected to have an economic bearing on countries in the region are raised 1 ow:

19 58 1964 1970 1976 1982 YEAR

Fig. 8. Sea surface temperatures (oC) - annual mean (Waglan Island, Hong Kong) (Nu. 1987)

47 1977 78 79 80 81 82 83 84 85 YEAR

Fig. 9. Annual mean sea level about chart datum at North Point, Hong Kong (Wu, 1987)

(a) Pollution caused considerable losses to the maricul ture industry in Hong Kong. Detailed losses during 1976 - 1986 are tabulated as follows:

Cause Total no. of Total loss Total loss incidents (tonnes) (in HK$) Red tides, algal blooms & oxygen depletions Coastal development 7 (e.g. reclamation, silting etc.) Oi 1 spi 11ages 5 132 4,038,000 Toxic discharges (from industries or accidents) TOTAL 54 270 11,648,000

(b) The clean up cost for the "Frota Durban" accident in 1985 paid by the Hong Kong Government (including dispersants, staff and equipment cost, transport and administrative cost) was estimated at HK$1.2 mi 11 ion (~K$7.80 = US$1.00). The cost was recovered from the ship owner. The operational resources involved in clearing the oil spill from the Evergrand" was 300 men, 20 craft and 10,000 gallons of dispersant, working continuously for 180 hours. The amount of oi 1 spi 1 led was 400 tons. The cost to clean up a recent oil spill of 50 tons off the east coast of Singapore was about S$400,000 (S$2.05 = US1.OO) . (c) The cost of restoring marine 1 i fe to the Singapore River and Kal 1 ang Bdsin was about S$300 mi 11 ion. In order to improve water quality in Tolo Harbour, the Hong Kong Government has agreed to spend HK$ 4 billion for : (a) dredging the river bed in the catchment area, (b) cont,*ol cof animal wastes and (c) improving the sewage treatment facilities.

(d) ihe cost of clean-up of oil spills in the Straits of Malacca, by Malaysia, amounted to M$260,756 for the 1975 SHOWA MARU Oil Spill and M$2,661,639 for the 1976 DIEGO SILANG Oil Spill. Penalties and fines levied on industries in Malaysia, for effluents discharged against the established standards, amounted to M$680,787 for the period 1979-1985. The dredging of harbours and estuaries in Malaysia, as a rssult of heavy siltation, was carried out at a cost of M$297 million for the period 1979 - 1983, the volume of dredge spoils amounted to 90.9 mil 1 ion m for the same period. A further expenditure of M$107.8 million is expected to be required for the continuation of the activity for the period 1985 - 1988, when about 27 mi 11 ion m of silt are expected to be dredged. Finally, we note below the potential economic consequences of various impacts on the coastal and marine environment: (a) Oil spills - Cost of clean-up; environmental damage in terms of loss of 1 iving aquatic resources, including the sensi tive eggs and larval stages which wi 11 form the future stocks of the fishery; damage to fishing gear; loss of 1 ivel ihood by fishermen; loss of revenue from tourism as a result of damage to recreational beaches; compensation; etc. (b) Industrial effluents - Environmental damage in terms of loss of marine and aquaculture resources; cost of restoration of the marine environment; fines and compensation. (c) Dredge spoils - Offshore dumping of dredge spoils from harbours and estuaries, in the absence of coastal hydrographic considerations, have frequently led to the rapid return of the dredge spoils to their original location; environmental damage caused by the dumping, especial ly in ecological ly sensitive areas, leadiig to losses of valuable aquatic resources; loss of livelihood for fishermen; etc. (d) Coastal reclamation - Resultant changes in coastal hydrography 1 eadi ng to erosion of other shorelines, particularly recreational beaches; loss of revenue from tourism; loss of valuable shel lf ish beds; compensation. (e) Sewage effluent - Leading to microbial contamination of shell fish beds and the resultant loss of export earnings from shel lf ish; increased cost to consumers of clean or depurated shellfish; loss of livelihood by shellfish fanners; human health problems resulting from the consumption of contaminated shel 1 fish; etc. (f) Eutrophication - A phenomenon that is often implicated in red tides and paralytic shellfish poisoning (FSP), which could invariably lead to loss of export earnings from fish and shel 1 fish, human health problems, and toss of 1 ivel ihood for fishermen and shellfish fanners.

9. SUMMARY I his report is> a first attempt to provide a perspective of the state of the marine environment in the East Asian Seas region, that is, the marginal seas surround-ing the ASEAN countries including Hong Kong (Fig. 1). The tropical seas covered by the report lie between the Asian mainland and the Austral ian continent, interspersed with some 20,000 islands. These islands plus tue sect-ionsof the Asian mainland that include Thailand and part of Malaysia and Hong Kong, harbour a population of about 300 million people, the majority of whom are coastal dwellers. Marine contaminants have been analyzed sporadically in water, sediments and biota. Results to date indicate generally low levels but with some noteworthy exceptions in some of the heavily used bays. Because of 1 imited capability in the region, a more comprehensive picture of concentration levels and trends of many contaminants remains to be developed. Some efforts are being taken to improve quality of data and manpower capability in the region through intercalibration and training. The major source of organic pol 1 ution in the region is sewage, much of which is discharged raw into coastal waters whether directly or through rivers and waterways. Elevated faecal coliform levels are detectable near population centres with the notable exception of Singapore which has waged a concerted effort to curb pol 1ution at source. Organic inputs from industries are considerable near industrialized areas, although there is no evidence that toxic contaminants are being released in high concentrations. Significant portions of coastal areas have been developed for residential, agricultural and industrial 1 and uses. Virtually no natural coast1 ines remain in Hong Kong and Singapore because of their high population densities. In the larger countries, coastal alteration is most pronounced at population centres. Where industries have developed, there is some evidence of industri a1 waste disposal at sea including mine tailings. However, this is not widespread as the region is not heavily industrialized. Litter is more evident, particularly near ports and harbours. Both ports and shipping lanes are exposed to some oi 1 contamination because of the lar e volume of petroleum products that transit the drea (approx. 3 mill ion bbls/day). A few major oi 1 spills have occurred in the region. While much of the transported oi 1 comes from other regions, oi 1 and gas production within Southeast Asia is significant, amounting to about 2 million bblslday and 5 bi 11 ion ft3/d respectively, nearly half of which is offshore. Some tin mining is carried out on the seabed, principally in Thailand. Southeast Asian nations are reliant on fisheries for a significant proportion of their protein intake. Thai 1 and and the Phi 1 ippines each produce about two mi 11 ion tonnes aiinually. However, due to over-exploitat ion and destructive fishing methods, some stocks have manifested a declining trend. Some efforts are now being taken to increase mariculture pr-oduction as an alternative. The sewage discharge mentioned above has led to eutrophication of some coastal waters. In recent years, more red tides have been reported in the region, although the link to eutrophication or sewage discharge has yet to be established. There is more direct evidence that eutrophication adversely affects benthic communities. Red tides are both toxic and non-toxic. A number of incidents involving paralytic shellfish poisonin9 have been recorded in virtually all the countries in the region. In several cases, the causal organism is the dinoflagel late P~rodiniu-m bahamense var. compressa. Elevated col iform counts in some coastal waters have been taken as an indication of the presence of pathogens in the water. Some pathogenic bacteria have been reported occasional ly , resulting in the closure cf swimming beaches. Chronic public health problems arise and an outbreak of hepatitis in 1985 in Hong Kong (-and China) has been associated with the consumption of she! lfish. More and more concern has been expressed at the destruction of productive ecosystems 1 i ke mangrove swamps and coral reefs. Since these are known to support fisheries, their continued degradation wi 11 have great repercussions. Efforts are now being made to conserve these habitats and in some instances, steps are being taken to rehabilitate them. It is hoped that the natural recovery process which normally takes decades may be shortened considerably. There have been a few major oi1 spi 11s. Natural catastrophes have a1 so been reported in the region. The annual cyclones have occasionally caused storm surges that have destroyed natural communities and human settlements.

All countries in the region are now taking measures to protect the marine environment, spearheaded by their respective environmental departments. Measures include pollution control at source, environmental impact studies, national and regional legislation to present and respond to oil spills, and adherance to internatonal conventions on the protection of the marine envi ronment . The establ ishment of marine protected areas is also now nore common.

With a rapidly expanding population, the stresses on the marine environment are 1i kely to continue. However, more and more resources are being conimi tted to environmental protection, so that the rate of degradation is being reduced. Indeed, in some cases a reversal of the trend has been achieved. More and more countries are realizing the high costs of pollution and it makes more economic sense to shift towards prevention rather than damage control.

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NAMES AND ADDRESSES OF TASK TEAM MEMBERS

Dr. Edgardo Dizon GOMEZ Dr. Rudolf S.S. WU Marine Science Institute Department of Applied Science University of the Philippines City Polytechnic of Hong Kong c/o U.P. P.O. Box 1 Kowl oon Diliman, Quezon City 1101 Hong Kong Phi 1ippines

Dr. Manuwadi HUNGSPREUGS Dr. Aprilani SOEGIARTO Department of Marine Science Indonesian Institute of Sciences Faculty of Science, Jalan Pasir, Putih No. 1 Chulalongkorn University Jakarta Phya Thai Road Indonesi a Bangkok 10500 Thai 1and

Mr. Alexander Ananda JOTHY Ms. Ella DEOCADIZ Freshwater Fisheries Research Centre Envi ronmental Management Bureau Batu Berendam 6th Floor, Philippine Heart Center 75350 Malacca East Avenue, Diliman Ma1 aysi a Quezon City Philippines

Ms. KUAN Kwee Jee Ministry of Defence Personnel Affairs Department MINDEF Building Gombak Drive Off Bukit Timah Road Singapore 2366